wˌaɪl ɪnvˈɛstᵻɡˌeɪɾɪŋ ɐ pˈɔɪzənɚɹ æɾ ˈɛdɪnbʌɹə zˈuː, dɪtˈɛktɪv ɪnspˈɛktɚ dʒˈɑːn ɹᵻbjˈuːz sˈiːz dˈæɹən ɹˈʌf, ɐ nˈoʊn pˈiːdəfˌaɪl, sˈiːmɪŋli fˈoʊɾəɡɹˌæfɪŋ tʃˈɪldɹən ænd dᵻsˈaɪdz tʊ ˈaʊt ðə mˈæn, ɪn spˈaɪt ʌv əʃˈʊɹɹənsᵻz ðæt hiː wˈɔnts tə ɹᵻfˈɔːɹm.
While investigating a poisoner at Edinburgh Zoo, Detective Inspector John Rebus sees Darren Rough, a known paedophile, seemingly photographing children and decides to 'out' the man, in spite of assurances that he wants to reform.