Primeval, Series 3 Episode 2

Three teenage boys break into the local haunted house daring one another to go further and further into the abandoned building. A creature attacks them, and in the aftermath the only survivor is arrested for murder. Cutter discovers that another anomaly will occur in the same building, and the team go to investigate. They discover that a creature from the future with the ability to camouflage itself resides there. Meanwhile, detective Danny Quinn arrests Connor and seems to have an unusual interest in the house.