Bounding on stage to the fading strains of Total Eclipse of the Heart, circuit stalwart Mark Olver instantly puts the crowd at ease: this guy knows what he’s doing. Although it takes me a while to get over the fact he looks the spitting image of Timothy Spall.The framing narrative is Olver’s unlikely second career as a serial killer, specialising in dispatching clowns. Coming over like Derek Raymond’s I Am Dora Suarez, only with more slapstick, it’s a little forced but is still bursting with wit and good turns of phrase (his description of stabbing someone with an umbrella is particularly good).What makes the show great is Olver’s audience banter, this time focusing on who we’d like to kill. He establishes early on that we’re capable of violence by giving each of us a tennis ball which we then lob at his unfortunate techie. Most of us are pretty good shots.A woman from Walthamstow confesses she’d like to off “Liz from work” and this reviewer found himself suggesting that the sulphur in match-heads is a cheap and plentiful source of poison. I literally have no idea how I know that.Best of all is when Olver asks audience member Frank if there was any section of society he’d like to kill. Frank turns out to be German. Awkward.Guaranteed to be different every time, Olver’s show will undoubtedly feel fresh whenever you catch it. The ending is a little drawn out and an unnecessary video clip from Russell Howard is as funny as one of his sketches in his TV show (ie NOT funny) but these are minor quibbles. It’s all about the banter. The banter, and the killing...