Arthur gets upset when he finds out that D.W. has to tag along on his fishing trip with their father. He then gets jealous of her when she catches more fish than him by using an unusual technique she came up with herself. One of D.W.'s socks goes missing, so Pal and Kate try to find it. The thief is revealed to be the Molinas' dog, Amigo, who tells them about the Sock Market, a parody of the stock market, and Pal tries to auction off socks from the house to get D.W.'s back.