Cris, Kam, Lindsey, Melina Cris, Kam, Lindsey, Melina

With only four contestants remaining on ABC's murder mystery show Whodunnit?, The Killer is getting a little more "experimental" with his riddles.

This week, Giles the Butler (Gildart Jackson) teases the remaining players — Melina, Cris, Lindsey and Kam — with a science project from the killer. Could a container of exploding ping-pong balls provide a clue into Ronnie's death last week?

Whodunnit?'s Giles: The Killer is "someone I completely overlooked"

See if you can pick up on any hints in this exclusive clip from Sunday's episode. Who do you think The Killer is?

Whodunnit? airs Sundays at 9/8c on ABC.