Well, Derek assumed that the veterinarian, who's also Scott's boss, is the Alpha. As you've seen Derek being attacked by the Alpha, the assumed Alpha was gone. This could lead to Derek's right instinct. However, I believe it's not the vet who is the assumed Alpha. I mean, there are some flaws in this episode. PLus, they're kind of nonsense to me. The scene where Derek goes through the usual way of how a human goes inside a house. Shouldn't Scott tell him to go through the window so that his mom won't see Derek along the way downstairs? Derek is kind of not the think-before-you-act type as he found the so-called evidence on his car window. And Scott and Stiles capable of breaking into the school? No way. Supposedly a bodyguard should be there at least. But, I'm still looking forward to what surprises in the next episode. Will I be able to see who the Alpha is? Tune in to find out.
P.S. I still don't believe that Derek is trying hard as it is clear that it doesn't look like it for Derek trying to get on Scott's good side. Soometimes don't anticipate an episode's sypnopsis.
Heart Monitor was a pretty good episode of Teen Wolf and I enjoyed watching this episode as Scott and Stiles attempted to practice heart rate control, the Alpha was on the move and causing trouble, and Scott gets more than he bargained for. There were some really great scenes and I particularly enjoyed how in this and the last few episodes the writing and directing has made it seem that a few people could be the Alpha, which makes me wonder if the others are just part of the pack or strangely human. In the end it seems Derrick is done for and who knows what will happen to Scott and Stiles. I look forward to watching the next episode of Teen Wolf!!!!!!!