Willis is hurt when he thinks his family has forgotten his upcoming birthday. After dropping several unsubtle hints he discovers that not only has everyone remembered, but also his fondest wish has been granted -- a birthday party in his old Harlem neighborhood.

Mrs. Garrett visits Kimberly's school and takes on its pushy principal with surprising results.

Arnold fears that his loved ones are checking out of his life when he stumbles upon Drummond's will and then uncovers the fact that his goldfish has given up the ghost.

Willis seeks comradeship as a member of the Tarantulas, a street gang, but finds only deceit as he gets caught in a web of misplace loyalties. Willis allows himself to be arrested rather than ""squeal"" on his fellow-gang members by telling the truth.

Dudley, fearing his foster father's lost job means he's headed back to the orphanage, cons Arnold into getting Drummond to consider adopting him into their family.

The coach of the city's top high school baseball team is after Willis and is prepared to do anything to make it possible for Willis to attend his school.

Blinded by love, Kimberly takes an enormous and deceptive risk when she talks her father into allowing her to move into an apartment, allegedly with her girl friend.

Arnold's feature story about his high school football team threatens to turn into a controversial expose for the school newspaper when he witnesses team members buying steroids.

Mr. Drummond and family gather around their Christmas tree and recall the many humorous incidents that the family has shared since Arnold and Willis moved in. This special one-hour episode features highlights from previous shows.

Willis and Arnold scheme to make extra ""dough"" by selling brownies, only to discover they can't stand the heat of big business and may soon have to get out of the kitchen.

Drummond runs into some stiff competition to the candidate he's chosen to head a new division of his company -- his board members think the attractive young executive's sex disqualifies her -- and his family thinks he's being used.

Willis' obsession with joining an ""exclusive"" high school club rocks the Drummond household and leaves several victims in its wake, including a shaken Arnold who takes his brother's ""insensitive"" actions to heart.

Their family and friends assembled, Phillip and Maggie meet at the altar, only to realize each has made a major mistake, in the concluding part of a special two-part story. Charlotte Rae, Dody Goodman, Janet Jackson and Nedra Volz, each of who had appeared in recurring roles on ""Diff'rent Strokes,"" return as their original characters for the Drummond nuptials.

A music instructor ""backs up"" Arnold after he claims to be an expert sax player in order to impress a girl.

Willis' cut-throat competitiveness with another boy at his gym leads him to a decision that he will very much regret, especially after it hurts Mr. Drummond and gives Arnold the right to say ""I told you so."" Baseball great Reggie Jackson makes his acting debut playing a key, but unsuspecting role in Willis' questionable scheme.

Guarding the school bully's girlfriend, Ramona, seems like a simple task to Arnold, until his natural Jackson ""charm"" creates some problems, Ramona falls head over heels for him and Herman, the bully, wants to rearrange his face.

Father and son are feuding over First Amendment rights when an outraged Arnold objects to a white supremacy organization speaking at his high school and a discerning Drummond can't support Arnold's fury on the basis of the American right to free speech.

Arnold's well-intentioned endorsement of Larry Alder's hosting talents to a New York TV big-wig gives Larry the opportunity of a lifetime and brings the family to the big apple. Larry's try-out as a New York television talk-show house may be doomed from the start, one disaster follows another and not everyone on the Alder team may be rooting for him to win the job. **Part two originally aired as an episode of "Hello, Larry".

Arnold learns the true value of a dollar when Drummond turns down his request to lend $4,000 to the apartment building doorman anxious to take part in an attractive business deal.

Stress is diagnosed as the cause of hard-working Drummond's frequent attacks of pain, but suddenly young, healthy and ""normal"" Willis learns that he, too, is a prime candidate for the same debilitating ""attacks.""

Arnold's on the outs with his best friend Dudley after he innocently offers to help his bashful buddy win the heart of a young lady -- who falls for Arnold instead.

A short visit to the United States by Phillip Drummond's Dutch cousin Anna and her son Hans becomes an eternity for Arnold and Willis, who are made scapegoats for cousin Hans' mischief.

When Mrs. Garrett decides her life as a housekeeper is unfulfilling, she ends up being a guest in the Drummond home, and then makes an important decision concerning the future.

Arnold doesn't know when to leave well enough alone after Willis comes to his rescue, he gets himself involved in an ""undercover"" scheme to capture the ""punks"" at school who have been harassing him.

Aunt Sophia's matchmaking unites an unsuspecting Drummond with her ""working-class"" hairdresser, but a slip of Arnold's tongue ignites charges that Drummond is a snob, turning a ""budding romance"" into a roaring feud.