Turn, Turn, Turn
In the eleventh season premiere, Eric and Annie receive devastating news on the prognosis on Eric's health. Ruthie (Mackenzie Rosman does not appear in this episode) is away on a student exchange program in a foreign country for the time being. Lucy and Kevin continue to cope over the devastating loss of their twin boys as Lucy had miscarriage over the summer.
Also, Martin (Tyler Hoechlin) returns back on the scene and is very protective of Sandy and the baby when she brings company home. When Sandy and Daniel arrive at her apartment Martin is very territorial among Sandy and baby Aaron and Daniel not being there. A confrontational Aaron admits to Martin that he was just a one night stand just for Sandy make Simon feel jealous, which leaves Martin at a loss.
Sandy decides that she wants to join seminary school. Also, last season's cliffhanger on the paternity of Aaron is resolved by Sandy. Lastly, Simon (David Gallagher does not appear in this episode) is away at college.
Also, here is some more from tv.com reguarding Mackenzie Rosman & David Gallagher's returning.
After the CW network un-cancelled and renewed "7th Heaven" after the now-default WB network, some regular cast members opted out of returning to the series when new contracts were constructed to lower the show's budget and salaries of cast and crew. David Gallagher (Simon Camden) and Mackenzie Rosman (Ruthie Camden) both declined to return to the series as regulars unlike last season. Although, they may appear part-time
Actor Tyler Hoechlin (Martin Brewer) returns to "7th Heaven" after his absence during the second half of the 10th season