A Vicar held the sevice for Reg Stevenson's funeral in 2015. At some point before this his body was hijacked by a Dalek mutant. During the initial service the Vicar aroused the suspicions of the Fourteenth Doctor after she noticed that he seemed weary and unfocused.
During the wake the Doctor, Erin Stevenson and Kyle Harrison learned about the mutant after the Vicar took the Doctor aside after spotting her snooping around. Soon after it freed the Vicar to hijack the TARDIS. (DW: Queen of the Daleks)