A recurring theme of Mr. Ed is that since Ed only talks to Wilbur, Wilbur can't explain how he gets into crazy situations and looks eccentric at best, and sometimes downright crazy. Addison talks Mr. Foster into considering Wilbur for a job as his head architect. Foster is everyone's favorite curmudgeon, Charles Lane, who played many of the clients of McMahon & Tate on Bewitched.
Wilbur can't see himself working for this hot headed guy for too long, but wants the security of a high paying job. He has a 3:30pm meeting with Foster but takes Ed to the park to fly his kite. When the kite gets stuck in a tree, Wilbur climbs the tree to get it down and falls into the lions cage when the tree limb breaks. The lion chases Wilbur around his cage and each time Wilbur passes behind a large rock he loses an item of apparel. Ed can't summon help because he doesn't talk to other people and has no dime for a phone call, so he steals a ladder from a worker in the park and throws it over the fence(How?). Wilbur climbs the ladder in his underwear, only to be confronted by the client, the neighbors and Carol. The ending is strange.
Mr. Ed is alone at the end with just himself and the lion, and he asks (in English) if the lion is glad he is safely in his cage and not among the goofy humans. The lion roars his assent, and the viewer is left to wonder why Ed didn't just tell the lion not to eat Wilbur.