In 743 (2020), Ben says that he "died 17 years ago." In this episode, it's revealed he died in 2006. Ben spent 13 years as a ghost from 2006 to 2019, 10 months with Klaus in Vietnam, and three years in the 1960s.
The overhead shot of the Hargeeves' walking into the courtyard for Ben's funeral directly parallels one from We Only See Each Other at Weddings and Funerals (2019), where they enter the courtyard for Reginald's funeral.
This is the highest rated episode of the series.