Only Murders in the Building introduced a surprising story line for Steve Martin's Charles - who is now on testosterone. During the Tuesday, September 23, episode of the hit Hulu series, Charles told Oliver (Martin Short) that his strange behavior was the result of the enhanced male hormone. "My doctor asked me if I wanted to join a trial group for guys my age," Charles said. "It's supposed to build bone strength and give you energy. I think [it is working]." Despite finding success with the results, Charles was also experiencing weird symptoms, adding, "My mouth tastes like pennies.