Indeed I noted that Tom and Allison are the only remaining original cast members to my friend at the start of this season. As many of us have noted...the show has come a long way. Sam Jones III was the first to leave. Then Jon Schiener was unfortunately killed off, Annette left, then John Glover, and finally Micheal and Kristen. I believe that is the chronological order. To be succeeded by Erica Durance, Aaaron Ashmore, Justin Hartley, Cassidy Freeman and as of one season (thank Rao) Callum Blue.