TG’s production of But Why Bump Off Barnaby? is a hilariously whimsical Knives Out style murder-mystery: aristocrat Orien LeDuc invites his family members to his spooky manor, and before long, long-absent Barnaby Folcey is murdered. An unlikely group of eccentric characters desperately try and unveil the mystery behind Barnaby’s death, the plot thickening at every…