Die Like a Dog - S2.E4

Archie stumbles onto a murder scene while trying to retrieve his raincoat. Not wanting to get involved, he leaves the scene only to discover a black Labrador retriever following him. Wolfe, surprisingly, is taken by the animal and christens him Jet. When Cramer shows up in search of the pet, wolfe gets Archie involved in the investigation in order to keep the dog.