The first episode in which Frost does not have a "one-off" new partner, however he is traditionally partnered in this episode (although on a temporary basis) by W.P.C. Wallace, who is seconded to C.I.D. to lend "female influence" to the rape investigation.
Final appearance of DCI Allen, one of the original characters and a major part of the novels on which the series is based (although as a twin DI with Frost). He is mentioned one more time in the third season by Mullett as "being away."
This is the only time in the entire series where Frost doesn't investigate a murder.