Rory Kinnear is one of those annoying people who can turn their hand to anything, if The Herd is anything to go by.

Not content with wowing the critics as Iago in the National's Othello, he's come up trumps with a cracking debut play.

The Bond actor is aided by a superb cast, especially Anna Calder-Marshall as the acid-tongued grandmother Patricia who steals all the best lines.

We join Carol (Amanda Root) waiting for her seriously disabled son Andrew to arrive for his 21st birthday party.

As the rest of the family assemble around her, some members more welcome than others, Kinnear squeezes every drop of awkward out of the scenario.

But he also reaches deep for the incredible joy and pain, often in the same breath, which is so unique to family life.

Kinnear's script, directed by Howard Davies, bears all the hallmarks of an old hand.

It's a well-paced look at the tribulations of parenthood and the power of forgiveness, packed with quotable, often very funny lines.

The highlight is an agonisingly funny, one-sided duel between Patricia and Andrew's absent father Ian, played by a whimpering Adrian Rawlins.

What's perhaps most remarkable, given the acute understanding of the huge highs and lows of parenthood, is that it was written before Kinnear himself became a father.

I must admit I had my pencil sharpened, ready to write this off as a vanity project and give this wannabe writer his directions back to the stage, but it seems in Kinnear the Playwright we have a genuine talent.

* The Herd is at the Bush Theatre until October 26. For tickets, call 020 8743 5050 or visit www.bushtheatre.co.uk .