Having hired Eric Catchpole as an apprentice, Lovejoy sets out to unravel the meaning of a Japanese firefly cage.As Lovejoy and Eric are in hot pursuit (on Eric's motorbike) of a lovely lady with something they want, they hit a pool of water in the road and give a drenching to Jane (Lady Felsham), who is busy unveiling a plaque. When, later, Lovejoy rings the doorbell at Felsham Hall, complex chemistry begins, and Jane is soon showing Lovejoy around her attic...