Mr. Wilson's Sister (S01E21)

S01E01 Dennis Goes to the Movies S01E02 Dennis and the Signpost S01E03 The Fishing Trip S01E04 Grandpa and Miss Cathcart S01E05 Innocents in Space S01E06 Dennis' Garden S01E07 The New Neighbors S01E08 Tenting Tonight S01E09 Dennis Sells Bottles S01E10 Mr. Wilson's Award S01E11 The Christmas Story (aka Dennis & Christmas) S01E12 Dennis and the Cowboy S01E13 Dennis Haunts a House S01E14 Dennis' Tree House S01E15 Dennis and the Rare Coin S01E16 Dennis and the Bike S01E17 Dennis and the Open House S01E18 Dennis and the Duck S01E19 Dennis and the Swing S01E20 Dennis and the Dog S01E21 Mr. Wilson's Sister S01E22 Dennis and the TV Set S01E23 Dennis Creates a Hero S01E24 Dennis' Paper Drive S01E25 Dennis and the Bees S01E26 Alice's Birthday S01E27 Dennis Becomes a Baby Sitter S01E28 Dennis and the Starlings S01E29 The Party Line S01E30 Dennis by Proxy S01E31 Dennis Runs Away S01E32 Miss Cathcart's Sunsuit