I had been warned ahead of time that Sark wasn't going to be in this ep (although I did half expect Weiss to tell Sydney to look him up, not Sloane), but yeah, I don't see how there was time for him. This was Sydney pulling her world back into some semblance of order and it needed to be done before anything else can happen. Other than the overly-long sequence on the train, the entire episode was Syd's POV and I really don't see Sark on Syd's list of priorities just then.