Fool, By Christopher Moore<br />The Final Act of Mr Shakespeare, By Robert Winder

Christopher Moore's Fool is a shaggy-dog story of rumpy-pumpy, a primal soup of violence and sex, the latter notably at the hands of a Quasimodo called Drool. He is the sidekick of King Lear's ever-resourceful Fool, the irrepressible Pocket. Drool either masturbates abstractedly in the palace laundry – he is eventually promoted to Royal Minister of Wank – or else, courtesy of Master Pocket, has bionic intercourse in the dark with Goneril and Regan, both under the mistaken impression that they are being bedded by a turbo-charged Edmund the Bastard. Regan, or "bunny cunny" in the Fool's all-licensed language, oozes sex. She is beautiful, murderous, insatiable, while her younger sister Cordelia, issued from one Lear's later marriages, has an unusually raucous sense of humour.

It is a dangerous world that Fool Pocket inhabits, but he is having fun too as his duties involve servicing Lear's daughters at various stages of their lives. His nether parts are drooled over by the pubescent royal harem long before "donkey-donged nitwit" Drool ever appears on the scene. In turn, teeny Fool Pocket loses his virginity to the hands and mouth of a Rabelaisian anchoress in the convent of Dog Snogging where he was raised as an orphan.

To reveal her true identity and how Lear's Fool relates to her and the King would be giving away too much of a plot which excels at springing surprises on the reader. For sheer madcap inventiveness, this novel verges on magic realism, never more so than when Pocket finds allies and guardian angels who cheerily quote the weird sisters from Macbeth as they chaperone Fool, Drool, and Kent through a cold, loveless, tyrannical England.

Shades of Blackadder and Baldrick stalk this helter-skelter ride which bristles with quotes, arch misquotes, and downright perversions of King Lear. While France and Burgundy, though wooing the king's youngest, prefer each other's company in bed, a psychotic Lear, not nearly enough sinned against, asks of the Fool, "You put your dick in my lunch?" Not a line of Shakespeare's, this one, but floating alongside them here in a brew of brilliant slang.

This Will-the-Bard bonk-romp cocks multiple snooks at the most venerated of Shakespeare's plays. It could not be more different from Robert Winder's stylish and richly suggestive The Final Act of Mr Shakespeare. In his prefatory "Historical Note", Winder concedes that his story is fictional, but not therefore necessarily untrue, citing in support Oscar Wilde's witticism that the only duty we owe to history is to rewrite it. Winder's novel and attached play are a labour of love or a love's labour's won, to cite the title of the least lost of Shakespeare's allegedly vanished plays, one that may well be buried under another name in the present canon.

In Winder's carefully crafted novel, we are plunged deeply into the wards, noises, stinks, river and moral flotsam of the London of 1613. It is a haunting narrative revolving around Will Shakespeare's decision, against his better judgement and in response to a gross act of bullying, to write one more play, another solo effort after The Tempest. Not Henry VIII, that allegedly lame-duck collaboration with John Fletcher, Shakespeare's successor as chief dramatist in the King's Men, but a play on Henry VII, the victor of Bosworth field, nemesis of Richard III.

Not that Henry VIII is dismissed here. On the contrary, it plays a pivotal part in the plot. If you want to know how the blaze that consumed the first Globe theatre on 29 June 1613 during a performance of Henry VIII really started, you will have to read to the end of this sweeping historical novel. Winder steers an artful middle course between Charles Nicholl's tales of Marlowe in the underworld on the one hand and AS Byatt's Possession on the other.

Byatt's literary classic, brilliant in its self-conscious interweaving of narrative layers, looms behind this delicate story of a dissident Shakespeare traumatised by a Stuart police state. Its cruel factotum Sir Edward Coke, the man who prosecuted Sir Walter Ralegh and became Lord Chief Justice in the year in which the novel is set, does not shrink from blackmailing the national poet. Which is why a defiant Shakespeare, joined by the chief players of the King's Men as well as by John Donne's daughter Constance and Edward Alleyn, sets about to write "Henry VII". Its explosive content makes it verge on high treason, revealing the darkest secret of the Tudor dynasty.

The play's crucial scene openly echoes the encounter in the Jerusalem chamber between a dying Bolingbroke and Hal in Henry IV part 2. The story of the secret was slipped to Will in an encrypted manuscript during a fleeting encounter in London. John Florio - translator of Montaigne, sage of Fulham, and quondam tutor of Southampton, Shakespeare's friend and dedicatee of his two narrative poems - eventually enters the fray on the side of the thespians as they take on the might of the state with the power of the pen.

Winder rarely puts a foot wrong in this tightly controlled narrative. He handles the blank verse of the fragment "Henry VII by William Shakespeare", put on at a hidden London venue, with impressive mastery, skilfully covering his artistic tracks in so doing. After all, only Shakespeare's own lines ever truly sing with the rhetorical elixir of Antony and Cleopatra and The Tempest.

René Weis is professor of English at UCL; his 'Shakespeare Revealed: a biography' is published by John Murray