Alice's September Song is the 23rd episode of Season 2 of The Brady Bunch, and the 48th overall episode of the series. Written by Elroy Schwartz and directed by Oscar Rudolph, it first aired 12 March 1971 on ABC.
Alice's old flame, Mark Millard, re-enters her life, wanting to sweep her off her feet, then presents her with an investment proposal that Mike senses may be too good to be true.
Alice receives a surprise telephone call from Mark Millard, her dashing former sweetheart from school whom she hasn't seen since those days, who wants to see her. Despite casually dating Sam, Alice decides to go out with Mark to see if that old spark is still there. Mark is as handsome and charming as Alice remembers. He wines and dines her, so much so that she thinks he will soon pop the question, which if he does, she is not sure how she will answer, partly because of Sam. While he doesn't pop the question, he does causally mention attending meetings about a prospective business investment, which will yield a profit if invested in, which excites Alice as well. Later, as she's preparing to go to the bank to withdraw money for the investment, she casually mentions the opportunity to Carol, who curiously asks about the business involved. Alice admits she has no idea, as she had got caught up in the moment, and didn't think to ask the necessary questions. Carol tells Mike about the suspicious investment, and Mike does some background checking on Mark Millard. He eventually uncovers, that Mark is trying to scam Alice, as he has a chronic gambling problem, and uses gullible female partners to support himself, and he's married and pulled his scam on six other women, to five of whom he's now paying alimony. Carol and Mike tell Alice, who feels stupid for almost buying Mark's scam. Mark arrives, and Mike reports to Mark that his friend from the D.A's office is on his way over for questioning. Mark tries to escape, but on his way out the back door, he hits his head on a frozen leg of lamb, being delivered by Sam the Butcher, and is knocked out. Sam apologizes to Alice for the mishap, but Alice wishes Sam had been carrying a whole side of beef. She casually gets revenge on Mark by pouring water from a watering can over his face, as Mike, Carol, Sam, and Mike's friend from the D.A's office look on. Meanwhile, the boys, with Mike's help, work on building a model airplane, but can't get it to fly in the yard. Sam and Alice take them and the girls on a picnic in the park to fly it.