Given the task definition and input, reply with output. Based on the given question and tppic, give an answer. The answer is available on on the internet. The questions are mostly centered around a single named entity.

concept: Spike  question:  who plays spike in buffy the vampire slayer?

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
['James Marsters']