Philip Ridley’s first play for three years, Tender Napalm is a tense, fantastical, sexual tussle between the unnamed Man and Woman, who have met at a birthday party and thread their attraction through a series of mythical games and tarantellas on a desert island.

At various stages, they face off with rival bands of monkeys, re-enact scenes of classical lore and cartoon savagery, sexual taunting and mutilation. Man went on a bender in the jungle. Each has visions of the child they were, or had between them. The tsunami did a lot of damage to their playground, where Man has tussled with Woman’s aunt, a killer serpent he defeats to a round of applause.

Above all, this is a challenge to actors, a wild scenario that Ridley has imagined as a video game with intense realism. And mop-haired, muscular Jack Gordon, who played the rent boy in Ridley’s recent urban fantasy movie Heartless, and Vinette Robinson, who sizzles like an electric eel, put on a great show of violent sensuality and non-stop energy over 85 action-packed minutes.

They start and end sitting on chairs, after the shipwreck, threatening to squeeze a bullet between those rosebud lips for a taste of metal and gunpowder. In between, they describe their own auto-erotic adventures, Woman rolling around naked on the beach and claiming her descent from the whales, while Man gets down with the aliens and zooms between planets and meteors.

The rollercoaster is eventually anchored in David Mercatali’s production in a lilting, lyrical song, “Fade and float”, (beautifully set by composer Nick Bicat) and in the fateful encounter at the party.

Perhaps the last quarter of an hour is over-freighted with Shoreditch and Essex detail, and the missing father figure on both sides doesn’t play with much dramatic significance. But this is a rough, raucous, verbally extravagant and sometimes shocking theatrical firecracker, and it makes you realise how pallid most theatre writing – and acting -can be when everyone’s on their best behaviour.