Colin Wilson, once the angry enfant terrible who conquered London's literary set with that socio-philosophical uproar, The Outsider, now proves himself a much-changed young man: saner, shrewder, not at all savage- in fact, almost dull. For if all his previous efforts might have had the tempestuousness of Existentialist thrillers, the current second novel appears to be nothing more than a sweet and slow Soho version of Kerouac's The Subterraneans. Pleasantly picaresque and smartly sentimental, Adrift floats all over the Thames city following its Midlands innocent, Harry, on a coming-of-age adventure, mixing with bohemians, beggars, blaggers and British Museum bibliophiles, just before settling in a Notting Hill flophouse with the usual ""revolutionary"" riff-raff. There's Blichstein, a devil worshipper; Eric, a bubbly sodomite; Charles, an idealistic rogue; Doreen, the New Zealand beauty for whom Harry falls, and Ricky, our hero's alter-ego, the true and committed artist, immured in his loft, swearing off women and the world, only to awake later on and find himself famous. Page after page sprinkles talk of socialism, Shaw, Zen, visions of Cartesian perfection, tea smoking, bloody landladies, wacky broads and one or two shots of hard sense. But despite all the engaging chatter and author Wilson's still canny style, Adrift in Soho is really as slight, synthetic and suspect as its locale.