- "You wanna a Pepsi, pal, you're going to pay for it."
- —Lou to Marty
On the morning of November 5, 1955, Lou was behind the counter at his cafe, serving breakfast to several diners, when Marty wearing what appeared to be a "life preserver" came through the front door and asked to use the payphone. Lou stared curiously when Marty's wristwatch made a strange beeping sound.
Marty tore a page out of the telephone directory and started asking Lou directions to Doc's home, the owner asking if he was ordering any food or beverage. Marty agreed to order something, he attempted to order a tab but Lou thought he was wanting a bill (often known as a "tab"), then asked for a Pepsi (free!), to which Lou thought he wanted a "free" Pepsi, and finally asked for "something without sugar". Lou served him a 5¢ cup of black coffee. The kid then asked Lou if he had any Sweet 'n' Low, which he described as "an artificial sugar substitute with no calories", but Lou said he didn't have anything like that. The kid then ran out of the cafe after one of the customers.
A couple of days later, with the cafe filled with customers after school, chaos erupted with Marty when Biff Tannen came into the restaurant, then ran out of the door. Lou stepped outside to watch, while Lou's employee Goldie Wilson ran over to see Biff's car collided with a manure truck.
Marty came into Lou's Cafe one final time on the night of November 12, shortly before closing time, bought an Almond Joy, asked to borrow some stationery, and sat down at a table to write a letter to Doc. Lou didn't see the time traveler again after that.
Sometime between 1955 and 1985, after the downtown in the popularity of diners, the cafe lost customers to fast food restaurants like Burger King, and Lou stopped selling burgers and shakes. By 1985, Lou's Cafe had been replaced by Lou's Aerobic Fitness Center, which attracted a steady supply of mostly female customers throughout the day due to the aerobics craze during the 1980s. It was not made clear if Lou was even still alive by 1985, if he had died and the current owner(s) merely kept the name, or if the center was simply owned by someone else named Lou (possibly a descendant). At some point between 1985 and 2015, someone revived the cafe as a theme restaurant, called "Cafe 80's", though what connection the Cafe 80's had to Lou (if any) was not mentioned.
Behind the scenes
- Lou Caruthers was portrayed by gravel-voiced comedian Norman Alden, who was 60 years old at the time that he was playing the role of a 1955 restaurateur, which would place Lou's date of birth sometime in 1895. Although Lou's Cafe was later replaced by Lou's Aerobic Fitness Center, Lou would have been 90 years old by 1985 and 120 years old by 2015, assuming he was still alive by that time. As of the start of 2015, there are no 120-year-old people on Earth — there were three women, born in 1899, who were 114, and the oldest of them, Jerelean Talley, died on June 17, 2015, shortly after her 116th birthday. The second oldest of them, Susannah Jones, died on May 12, 2016, roughly two months before her 117th birthday, leaving the youngest of the three, Emma Morano, as the last living person to be born before 1900. Only three people survive from the 19th Century, including two born in 1900.