Unpredictability is what keeps rock alive, and the Libertines have it seeping from every pore. Just look at Pete Doherty: in the past six months he has broken into bandmate Carl Barat's flat, emerged from prison to rejoin the fold, and now here he is at the Forum, radiant, bouncing about like a cockney barrow boy and sharing vocals with support act Chas 'n' Dave. The daffy ragtime'n'roll duo are in robust form, but every jolly knees-up they play sounds exactly the same. Every punk-thrash brawl in the Libertines' set follows a single blueprint, too - but they give the impression of electrifying variety because you never know what Barat, and particularly Doherty, will do next.
Bring on a stocky, hirsute chap called the Rabbi to growl out Sally Brown? Decide that, since a guitar has managed to detach itself from its shoulder strap, you might as well chuck it into the crowd? Par for the course at this gig.
It's Doherty who throws the guitar, and it's Doherty who proves most riveting to watch, if only because it's such a pleasure that he is still in the band. Barat, you feel, could succeed alone through sheer force of ambition. But it's the interplay between the two frontmen, prowling about as though squaring up for a fight, that makes this gig so shiveringly exciting. They kick each other, throw their arms about each other, finally kissing each other at the start of The Good Old Days, which they sing gazing into each other's eyes, tearing away to snarl in delicious disdain against the "list of things we said we'd do tomorrow".
Tomorrow, of course, is the real test, but the new songs here - the glinting Last Post on the Bugle, the impossibly frantic Arbeit Macht Frei - suggest that the next album will have all the bite of Up the Bracket. But it relies on Doherty and Barat staying together. At the end of the gig, Barat tips Doherty into the crowd, then dives in after him. Their guitars lie buzzing on stage, leads messily - and, with any luck, prophetically - entwined.
· Ends tonight. Box office: 020-7344 0044.
