Marc Blucas portrays the character of Riley Finn. Riley was introduced in the season four premiere episode, "The Freshman" as the Psychology Teacher's assistant. Buffy made an exceptional impression on him as she dropped a stack of books on his head, and then proceeded to make a fool out of herself by saying less than intelligent things. At first, he found a common interest with Willow, but has since opened up slightly to Buffy and offered some friendly advice on how to get by in Psychology class.

It was later discovered that Riley was a member of a underground operation called "The Initiative." Under the leadership of Professor Walsh, the group captures demons of Sunnydale and experiements on them. As Riley grew more interested in Buffy, he found it harder to keep his secret life...a secret. Finally, in the episode "Hush" Buffy and Riley ran into eachother on the job and later revealed to eachother their secret identities.