One day, SpongeBob takes Gary to a snail park where Gary falls in love with a snail named Mary. Then Mary's ex-boyfriend threatens Gary but Mary ignores him and falls in love with Gary which angers the other snail and tells Gary "When I'm done with you, your doctor will not know where to sow your lips back on." Then, SpongeBob comes and tells Gary they are leaving along with Mary's owner. At nighttime in SpongeBob's House, SpongeBob feeds Gary dinner and they go to bed.
The next day, Gary sneaks out of the house to find Mary. SpongeBob awakes to find a picture of Mary which he thinks is Gary leading them to think that it is a ransom note from a snailnapper, so he sets out to "save" Gary. Meanwhile, Gary stays onto a sidewalk with dozens of snail owners having a stroll. Then he sees Mary's owner going into a pet store and goes in. The clerk thinks he is a stray and puts him on sale. A few seconds later, Mary's Ex-boyfriend and his friends ransack the store so that the clerk can tell him where Gary is. During the ransack, Gary escapes. The other snails see what appears to be Gary, only to find out it is a vicious poodle worm.
Gary then sees Mary but sees her in a car and jumps on top of other cars in order to find her. They succeed, but SpongeBob finally finds them, along with the other snail. Then, a man from a soap opera Gary was watching in the beginning finds Mary's owner, who turns out to be his lost love. Beside him is a handsome snail which Mary gets together with, which SpongeBob says to Gary, "That's gotta hurt, Gary" and the other snail forgives Gary and becomes friends with him by asking Gary if he wanted to go get seaweed noodle stew with him. The episode ends with SpongeBob saying "they grow up so fast."