Lee, to summarize:
Sandy hid Rebecca's existence from Kirsten ostensibly to keep her from being an accomplice to harboring a fugitive. He agreed to find a way to clear her name, or at least plea bargain so she had time to spend with her dad before he died. The cliffhanger was Kirsten discovering that Rebecca was in fact still alive and camping out in Sandy's office.
Meanwhile, Kirsten engineered another dinner with Caleb to set things straight with Lindsay. He predictably got into a verbal battle with Ryan and then had a heart attack, which made him feel all gooey and second-chance-like. So apparently now he actually wants to have a decent relationship with his daughters.
Seth, on the other hand, almost kisses Summer during their little drawing fest. Zack is giddy the entire episode because Wildstorm is interested in producing their comic. Seth and Summer are realizing things can get weird.
And finally, Marissa and Alex hold hands so they can kiss in THE LAST FIVE MINUTES of next week's episode.