In the film, Callan's boss Hunter is played by Eric Porter, and Meres too is re-cast, this time played by Peter Egan (known at the time as a trendy gangster, from the controversial TV series "Big Breadwinner Hog", but now better known for sitcoms such as the BBC's "Ever Decreasing Circles"). The only recurring actors from the TV series were Edward Woodward as Callan, Russell Hunter as Lonely, and Clifford Rose as Dr Snell (who appears in five of the television episodes from series two, three and four – although in the film, reflecting the screenplay's 1967 origin, it's stated that Callan has never met Snell before).