A quirk of timing saw two major productions of King Lear take to the stage at the same time this week. One is at the Old Vic where, at the age of 80, the former Labour MP for Hampstead and Highgate, Glenda Jackson, returns to theatre after a 25-year absence. The other is at the Barbican where Antony Sher leads the Royal Shakespeare Company's latest production of the tragedy.
On the press night, the RSC began at the earlier than normal time of 7pm - the usual time for the Old Vic. So, at exactly that moment, two utterly different Lears began the descent from absolute power to nothingness. And having seen Jackson's it was impossible not to remember her as Sher performed his; knowing that as Sher's Lear appeared swathed in fur as deep as a snow drift and carried by bearers in a glass box like the Pope, Jackson was walking busily and barefooted into the same opening scene, her agile, fragile frame elegantly resplendent in a silky, feather-light trouser suit - her own clothes, I'm told.
It is an astoundingly brave comeback, certainly. There is a quickness and energy to the body; a strength and clarity to the voice that to Jackson must have felt like a terrible waste had she never returned to the stage.
Yet her Lear is more fascinating than moving. And I don't think that is anything - or much - to do with Jackson being a woman playing a man. One of the finest Falstaffs I've seen was Ashley McGuire in the Donmar's all-female Henry IV. But there is an underlying sanity to Jackson's Lear right from the off, that makes you wonder how on earth she is going to go mad.
It's a minefield to pick out gender-specific characteristics. But there is a stupidity to Lear that is, well, male. And although, despite the stamina-sapping length of Warner's production, Jackson's Lear directs a withering ferocity to her betraying daughters (a post-punk Jane Horrocks and a suburban Celia Imrie), Jackson never quite manages to suppress the innate intelligence she brings to her acting.
For, as Rhys Ifan's ruthlessly honest Fool points out, there is no fool greater than Lear, an observation that feels much more pertinent to Sher's Lear than Jackson's.
Sher's is all growling bluster and pride. With a voice that sounds like a coffee grinder, he is a lion that is all mane and no bite.
There's a psychological sure-footedness to Gregory Doran's RSC production that is largely absent from Deborah Warner's at the Old Vic. Perhaps that is in part due to the sheer strength of the performances supporting Sher.
As Gloucester, David Troughton is superb. He is such a bully to his bastard son, Edmund, it makes complete sense of the son's conspiracy - executed with a winning wit by Paapa Essiedu.
At the Old Vic, however, the normally excellent Karl Johnson is a comparatively underpowered Gloucester, while Simon Manyonda's Edmund exhibits his buttocks and ejaculates as he declares his cunning plan to topple his brother.
All this - and the pared down set with its huge flat white panels - might open up Warner's production to accusations of gimmickry.
But it feels like an experiment set in a laboratory, fascinating but emotionally lacking. Opt, if you have the choice, for Sher's richer, more tragic and pitifully pathetic Lear.