I quite like it. True, it's very dialogue heavy, but the dialogue isn't bad (I've certainly read worse.) For some reason, the way Dr. Caldwell was written I kept reading him in Stephen Fry's voice. :/

There's nothing really wrong with writing fan fiction, it does get quite a bad reputation because the majority of it is awful. But there are some gems inside the manure pile that is fan fiction, it just requires digging and a talent for telling stories. As well as good spelling, there are loads of fan fics I've seen with terrible spelling and punctuation.