Killer Instinct, 8.30pm, Arena Arachnophobes, beware. A woman is paralysed with fear when she wakes to find two gigantic funnel- web spiders crawling on her face and bare shoulder. But the spiders are just the beginning of her troubles, and ours, as there’s a spiderwielding killer on the loose. He puts the revolting things under his victim’s doors and sics ’ em, Rex. Meanwhile, detective Jack Hale ( Johnny Messner) is working out hard in his home gym. He alone notes the similarities in a series of murders of young women and leaps into his clothes to take on the world, with acting nearly as wooden as his chiselled physique. Shorts on Screen, 12.05am, SBS Tonight’s shorts include Dance Mania Fantastic , about a young Japanese banker who cannot bear the shame of telling his family he has been fired, and Cool Water , in which a young couple’s day at the beach is complicated by an uninvited third person.