While investigating a THRUSH plot to sabotage space shots, Solo and Illya are incapacitated by a quartzite radiation projector. Waverly assigns new trainee April Dancer along with over the age of retirement agent Mark Slateto find the antidote and destroy the plan. April infiltrates the cosmetics company of THRUSH agent Arthur Caresse as a model, but she is uncovered by Caresse's sister Jean.