Arnold and Gerald are cast as a banana and a strawberry in their school play which is written and directed by Helga. Arnold wrecks Eugene's brand new bike.

Helga accidentally drops her journal full of love poems about Arnold into a pile of Gerald's books. Arnold and Gerald discover the journal and are astounded to find Arnold the object of such ardor. The boys are determined to find out who wrote the poems. Meanwhile, Helga desperately tries to recover the journal before Arnold reads the last page -- the one with her signature on it. Arnold's class goes on a field trip to the aquarium where Arnold waits in anticipation to see Lockjaw, the infamous "terror of the deep." When Lockjaw turns out to be an old tortoise with a graffiti covered shell, the other kids make fun of him and pelt his shell with garbage. Arnold feels sorry for him and conspires with Grandma to free the 400 hundred pound tortoise.

Helga tries to hide her disappointment at not being invited to Rhonda's makeover party. / Arnold gets caught between his loyalty to Grandma and a promise to help his pal Ernie demolish an old theater.

Arnold and Gerald are invited to a school dance by Connie and Maria; a pair of 6th grade "older women" who are trying to make their boyfriends jealous. The jilted boyfriends confront Arnold and Gerald at the dance. Arnold and Gerald manage to scrape up enough money for cheap seats at the last baseball game of Mickey Kaline - Arnold's idol. After making a dash for the expensive seats, Arnold snags a home run ball Kaline belts over the left field fence. Arnold has every intention of holding on to his prized possession until he learns the home run ball would mean even more to somebody else.

Heat: Arnold has a really bad day - the city is suffering from a heatwave, and whatever he does, Arnold just can't seem to get cool. Snow: Snow hits the city and Arnold can't wait to get out and have some fun... but wait, there's chores to be done... and when there done Arnold has the time of his life playing Hockey with the "crew".

Arnold decides to get up the nerve to speak with the girl of his dreams, Ruth McDougal, at the annual cheese festival. Helga learns of Arnold's infatuation and begins "Operation Ruthless" - every time Arnold attempts to approach Ruth, Helga spikes his plans. Arnold and the gang clean up a vacant lot so that they can have a baseball field, but the neighborhood adults have designs of their own for the newly renovated space.