General sadness and reminiscing. Josh and Santos had a spat over whether or not Santos should get involved in the race for Speaker of the House (that was two weeks ago).
Last week, Josh was stressed. He went to see Sam to ask him to be his deputy. Sam said he'd think about it (he's living in California, engaged, etc.). Meanwhile, Josh and Donna are still sleeping together, but Donna (who has been offered the position of Mrs. Santos's Chief of Staff) gives their relationship four weeks to materialize into something; if that time passes and they still haven't figured out what they want from each other, it wasn't meant to be. So, Josh is stressed and spastic. He's got a ton of stuff to do before the inauguration, and ends up blowing up. Sam shows up and gives him an ultimatum: he will be Josh's deputy under one condition, that Josh take a vacation. So Josh gets on a plane. With Donna.
Meanwhile, Santos and Bartlet secretly played a little good cop/bad cop with the Kazakhstan situation behind the backs of their respective chiefs of staff.
That should bring you up to date.
http://www.televisionwithoutpity.com has good, snarky summaries, but they're quite long. But if you want detail, it's pretty good.