1. Extra Textual facts.
Haggard is best known for writing adventure novels of the "Lost World" sub-genre, especially King Solomon's Mines (1885) (which introduced Allan Quartermain, the quintessential fictional British explorer) and She (1886) and their various sequels. Dawn, his first novel is not that; it's a very English crime/romance story with some scenes set in Madeira. According to the Wikipedia page, Haggard and his wife saw "a singularly beautiful and pure-faced young lady" in church and decided to write fan-fic about her. It was 1882; one had to make one's amusement where one could.
2. What is it like?
Dawn is Haggard's first novel. On a line-by-line and even chapter-by-chapter basis the book is very fluently and clearly written, with characteristic Victorian prolixity. Yet it's pretty awkward as a novel. It's nearly 200,000 words, which is far too long for the plot and characters to carry the story. It spends the first fifteen chapters on the rivalry between cousins, issues of inheritance, jealousy, a secret marriage etc. etc. all of which are okay I guess, but this means that we wait nearly a quarter of the book for our heroine Angela Caresfoot to be born.
Then we skip forward twenty years and finally the story gets going. The various schemes the elder generation have been gestating for that time start to come together and our hero Arthur Heigham arrives to fall in love with Angela. There follows a rather complex plot in which Angela's cousin attempts to split them apart so he can marry her, which her father passively accepts in order to regain the lands his father alienated from him, at a 75% discount.
3. What is there to like?
It has all the concerns of class, property and propriety that upper middle class Victorians swam in, but has a bit more self-awareness of the tensions these created than most of the other ones I've read. There's a good dog and a bad dog. Mostly a serious, even melodramatic, story there's a tiny bit of comic relief. I don't think it's intentional that both ladies who travel to Madeira without a gentleman escort bring with them an older and stouter companion who is a bad sailor, but it amused me. Mildred Carr, rival for Arthur's affections, reports a marriage proposal from Lord Minster in the following manner:
He stood like this, with his hands in his pockets, and said, 'I am now a cabinet minister. It is a good thing that a cabinet minister should have somebody presentable to sit at the head of his table. You are presentable. I appreciate beauty, when I have time to think about it. I observe that you are beautiful. I am not very well-off for my position. You, on the other hand, are immensely rich. With your money, I can, in time, become Prime Minister. It is, consequently, evidently to my advantage that you should marry me, and I have sacrificed a very important appointment in order to come and settle it.'"
She turns him down. Later he explains his political philosophy which mirrors this in a much less amusing fashion.
Believing Arthur dead, Angela agrees to marry George, but insists on this as a pre-nup:
"I, George Caresfoot, hereby solemnly promise before God that under no possible circumstance will I attempt to avail myself of any rights over my cousin, Angela Caresfoot, and that I will leave her as soon as the formal ceremony is concluded, and never again attempt to see her except by her own wish; the so-called marriage being only contemplated in order to enable me to carry out certain business arrangements which, in view of the failing state of my health, I am anxious to enter into."
Haggard characterises this as "...surely the oddest marriage contract which was ever penned..." I'm going to guess he's wrong on that one.
The various pieces all come together satisfyingly in the style of the-final-act-of-a-farce and the novel very nearly becomes a tragedy, but it turns out there are twelve or thirteen more chapters to wrap everything up and give us something a little happier.
4. Does it have any adventure-type bits like in his later novels?
There are a couple of genre-type bits. Almost irrelevantly to the plot, deputy villain Lady Bellamy reads the stars and claims to have really powerful magic which can only work if you give up all passions; she offers her knowledge to Angela at very nearly the end of the novel. Angela turns it down to go off and marry Arthur.
Angela also has this dream which is pretty cool:
First, it would seem to her that she was wide awake in the middle of the night, and there would creep over her a sense of unmeasured space, infinite silence, and intense solitude. She would think that she was standing on a dais at the end of a vast hall, down which ran endless rows of pillars supporting an inky sky which was the roof. There was no light in the hall, yet she could clearly see; there was no sound, but she could hear the silence. Only a soft radiance shone from her eyes and brow. She was not afraid, though lonely, but she felt that something would presently come to make an end of solitude. And so she stood for many years or ages—she could not tell which—trying to fathom the mystery of that great place, and watching the light that streamed from her forehead strike upon the marble floor and pillars, or thread the darkness like a shooting star, only to reveal new depths of blackness beyond those it pierced. At length there came, softly falling from the sky-roof which never stirred to any passing breeze, a flake of snow larger than a dove's wing; but it was blood-red, and in its centre shone a wonderful light that made its passage through the darkness a track of glory. As it passed gently downwards without sound, she thought that it threw the shadow of a human face. It lit upon the marble floor, and the red snow melted there and turned to blood, but the light that had been its heart shone on pure and steady.
Looking up again, she saw that the vault above her was thick with thousands upon thousands of these flakes, each glowing like a crimson lamp, and each throwing its own shadow. One of the shadows was like George, and she shuddered as it passed. And ever as they touched the marble pavement, the flakes melted and became blood, and some of the lights went out, but the most part burnt on, till at length there was no longer any floor, but a dead-sea of blood on which floated a myriad points of fire.
And then it all grew clear to her, for a voice in her mind spoke and said that this was one of God's storehouses for human souls; that the light was the soul, and the red in the snow which turned to blood was the sin which had, during its earthly passage, stained its first purity. The sea of blood before her was the sum of the scarlet wickedness of her age; from every soul there came some to swell its awful waters.
At length the red snow ceased to fall, and a sound that was not a voice, but yet spoke, pealed through the silence, asking if all were ready. The voice that had spoken in her mind answered, "No, he has not come who is to see." Then, looking upwards, she saw, miles on miles away, a bright being with half-shut wings flashing fast towards her, and she knew that it was Arthur, and the loneliness left her. He lit a breathing radiance by her side, and again the great sound pealed, "Let in the living waters, and cleanse away the sins of this generation."
It echoed and died away, and there followed a tumult like the flow of an angry sea. A mighty wind swept past her, and after it an ocean of molten crystal came rushing through the illimitable hall. The sea and the wind purged away the blood and put out the lamps, leaving behind them a glow of light like that upon her brow, and where the lamps had been stood myriads of seraphic beings, whilst from ten thousand tongues ran forth a paean of celestial song.
Then everything vanished, and deep gloom, that was not, however, dark to her, settled round them. Taking Arthur by the hand, she spread her white wings and circled upwards. Far, far they sailed, till they reached a giant peak that split space in twain. Here they alighted, and watched the masses of cloud tearing through the gulfs on either side of them, and, looking beyond and below, gazed upon the shining worlds that peopled space beneath them.
From the cloud-drifts to the right and left came a noise as of the soughings of many wings; but they did not know what caused it, till presently the vapours lifted, and they saw that alongside of and beneath them two separate streams of souls were passing on outstretched pinions: one stream, that to their left, proceeding to their earthly homes, and one, that to the right, returning from them. Those who went wore grief upon their shadowy faces, and had sad- coloured wings; but those who returned seemed for the most part happy, and their wings were tipped with splendour.
The never-ending stream that came flowed from a far-off glory, and that which returned, having passed the dividing cliff on which they stood, was changed into a multitude of the red snow-flakes with the glowing hearts, and dropped gently downwards.
So they stood, in happy peace, never tiring, from millennium to millennium. They watched new worlds collecting out of chaos, they saw them speed upon their high aerial course till, grown hoary, their foundation-rocks crumbling with age, they wasted away into the vastness whence they had gathered, to be replaced by fresh creations that in their turn took form, teemed with life, waxed, waned, and vanished.
At length there came an end, and the soughing of wings was silent for ever; no more souls went downwards, and none came up from the earths. Then the distant glory from which the souls had come moved towards them with awful mutterings and robed in lightning, and space was filled with spirits, one of whom, sweeping past them, cried with a loud voice, "Children, Time is dead; now is the beginning of knowledge." And she turned to Arthur, who had grown more radiant than the star which gleamed upon his forehead, and kissed him.
Then she would wake.
Finally Mildred has an interest in beetles, and also mummies. This doesn't really drive anything, but her Egyptian antiquities cellar does give her a cool and thematically appropriate place for her final despairing scene.
5. As a Victorian novel does it have a slightly heavy-handed moral?
If it does then it seems that men should only marry women of supernatural beauty, absolute virtue and an education in Classics and Mathematics. Otherwise, just become the toyboy of a rich widow.
Everyone goes through the wringer in this one, good or bad. Everyone who loves Angela suffers; everyone who tries to do her harm suffers more. Mildred, who sacrifices her own love and happiness for our hero (and his heroine), she gets her reward in the final line of the novel:
And Mildred? She lay there before the stone symbol of inexorable judgment, and sobbed till the darkness covered her, and her heart broke in the silence.
Read this book: If you want a maybe-better-than-average Victorian melodrama, are interested in H Rider Haggard, or anything I've said above sounds intriguing.
Don't Read this book: If long Victorian prose turns you off, or badly structured, slow moving stories annoy you, or grim and unpleasant deaths make you unhappy.
The good news: Published in 1884 (Haggard earned £10 for it) it is out of copyright and available for free online. Also it was made into a film in 1917 (during Haggard's lifetime. Maybe I should try and find out what he thought of that!). My half-hearted attempts to find the film leave me questioning whether it still exists or if it's simply a catalogue entry.
 Which popularised the name She-Who-Must-Be-Obeyed, re-popularised and re-contextualised in John Mortimer's Rumpole of the Bailey.
 Angela was also the name of Haggard's eldest daughter.
 Angela is the daughter of Philip, the son of Old Devil Caresfoot. George, who wishes to marry her, is the son of Old Devil's idiot brother and a kitchen-maid who seduced him (the relationship described in the book as a mesalliance), making him Angela's First Cousin Once Removed.
 Not his actual name.
 They fight and the bad dog dies, which is a pity as he, Snarleyow, was the most interesting part of the three chapters he was in. Also the good dog dies as well, defending Angela. Sorry about that.
 Named after a novel by Frederick Marryat; ON THE LIST (now)
 I do like an awkward marriage proposal; this is one is great for the total lack of self-awareness. Say what you will for one that lists the mutual societal and material benefits with not a single nod to love, passion or affection, they're straightforwardly explaining what each party will gain from it. Lord Minster has no thought for what Mildred might want.
 I don't think there are any easy parallels with Haggard's life here.