Grantchester star Tom Brittney was pictured back on set of the hit period drama in Cambridgeshire on Tuesday. The actor, 31, was seen filming scenes with co-star Robson Green, 57, and a baby, who is believed to play his stepson on the show. Tom and Robson were spotted at one point mucking around on set and throwing around a fake baby, which at times stood in for the bub, having a laugh in between takes.