In the first book about her, The Bigger They Come (1939; British: Lam to the Slaughter), Bertha Cool opened her detective agency after the death of Henry, her husband, in 1936. She is described in various terms as overweight, and uncaring about her weight—in the first novel, Donald Lam estimates her weight at 220 pounds. At the beginning of Spill the Jackpot (1941), she had flu and pneumonia, and lost a great deal of weight, down to 160 pounds, and in many later novels, her weight is given as 165 pounds. She has white hair and "greedy piggish eyes". All the novels agree that she is extremely avaricious and miserly. However, she has persistence, loyalty, and nerve. Her favorite expletive is some variant of "Fry me for an oyster!" or "Can me for a sardine!". In the opening chapter of the first novel, she hires a small, nervy, and extremely ingenious former lawyer named Donald Lam. Donald later becomes a full partner in her business, forming the agency, Cool and Lam, which features in more than two dozen books by Gardner.
Donald Lam is a fictional American detective created by Erle Stanley Gardner under his pen name A. A. Fair. In her biography of Gardner, Dorothy B. Hughes wrote, "Erle said over and again that if Donald Lam, 'that cocky little bastard,' had a model, it was Corney"—Thomas Cornwell Jackson, his literary agent. Jackson later married actress Gail Patrick, and they formed a partnership with Gardner that created the CBS-TV series Perry Mason.
Donald Lam begins his adventures as the employee of Bertha Cool, a stout widow in her 60s who started a detective agency in 1936. As a detective, Lam is in stark contrast to the fictional hard-boiled types of his era. Donald is about 5'6", weighs 130 pounds soaking wet, and gets beat up quite frequently. While he does get into several fistfights, he loses all but one — a single fistfight against an insurance investigator in Double or Quits, only after taking boxing lessons from a former pug named Louie Hazen in Spill the Jackpot, and studying jujitsu with a master named Hashita in Gold Comes in Bricks.
Donald does not carry a gun because, as he says: A) "A gun, a good type of gun such as I would want to carry, costs money", and B) "People are always taking it away from me and beating me up" (meaning the gun). His primary weapon is his brain, not his brawn. In the first book (The Bigger They Come), Donald tells Bertha that when people mistreat him, he uses his ingenuity to figure out a way to get even. He shows that frequently in his cases.
The early history of Donald Lam is murky, though several clues are given in the first novel, The Bigger They Come. He is known to have been a lawyer who had his license to practice law suspended for a year for casually mentioning to a client (who turned out to be a gangster) that he, Donald, had worked out a way to commit a murder in such a way nobody could do anything about it. This was a defect in the law itself, not a sealed room or a traceless poison or a way of vaporizing a body, etc. This theory was put to the test in the same book, when Donald confessed to a murder he did not commit to flush out the real killer. This was the same gimmick that Gardner's pulp character Ed Jenkins used, to stay free in California, while being a wanted man in seven other states. Fortunately for Donald, his theory stood up in court and he was absolved.
After his law license was suspended, Donald was desperate and started answering ads for jobs "that were just a little bit fishy on their face." This led him to Bertha, who hired him, and made money on him ever since. Bertha also uncovered Donald's past, including his real name, something that was never revealed. Donald apparently considered that a false start to his life. However, his legal training proved invaluable in later books, when he advised lawyers, or his clients, in trials as in Beware the Curves and All Grass Isn't Green.
Donald eventually became such a moneymaker for Bertha that she was forced to relent when he put the pressure on her for a full partnership in Double or Quits. When Donald originally asked to be made a partner, Bertha turned him down cold. So, Donald quit and moved to San Francisco. Bertha would have kept Donald on at a hired man's wages forever, but when he quit, she realized that he was her cash cow. Bertha tracked him down and begged him to return in exchange for a partnership. Donald acted uninterested, but finally allowed himself to be persuaded after making a couple of insulting additional conditions for his return. Bertha bit her tongue and accepted, finally confirming his dominance over his formidable boss.
This same book, Double or Quits, is about a case involving double indemnity "in the event of death by accidental means". Donald knew the legal difference between "death by accidental means" and "accidental death", which netted Cool and Lam over $40,000. Solving the case nearly cost Donald his own life, but he did find the proof to get the money, as the murder was held to be a death by accidental means, and the insurance company paid up.
At the conclusion of Owls Don't Blink, set in early 1942, Donald left the agency to enlist in the Navy and fight the Japanese after Pearl Harbor. Two books were written about Bertha alone, during the time Donald was serving his country: Bats Fly at Dusk and Cats Prowl at Night.
In Bats Fly at Dusk, Bertha takes a case brought to her by a blind man. Donald was able to correspond via telegraph, and gave her solid advice, much of which Bertha rejected. However, she finally quit the case at the end, only to find that Donald, on a military pass, flew down and solved it for her. The second, Cats Prowl at Night, put Bertha in a case that kept getting worse for her. She eventually came up with a single clue that led her to the solution, but showed she was not Donald's equal in such situations. After over two years of fighting, Donald was discharged from the Navy on medical grounds after he contracted malaria in the South Pacific, at the start of Give 'em the Axe. He returned to Los Angeles and went back to work, although he continued to suffer from frequent malarial attacks for some time.
Like Perry Mason, Donald firmly stood behind his clients, even if they have not given him all the needed information, or even if he did not like them personally. He worked according to his own sense of honor and loyalty, giving fair treatment to those who treated him well, and not caring about those who treated him poorly. His unorthodox methods and secretiveness frequently frustrated Bertha, but in the end, they paid off in earnings for the agency. Donald often became romantically involved with beautiful women connected with his cases - but only after the case was closed - and by the next novel they had dropped out of his life.
Donald Lam is dedicated to his ideals of justice. It may not always be the legal or moral definition of justice (in Beware the Curves Lam accepts without comment the wrongful conviction of a man for a certain crime, because he knew the man was actually guilty of murder), but to his unique sense of justice, the punishment seems fit the crime, at least in his own opinion.
Turn On the Heat was adapted by Welbourne Kelley for the June 23, 1946, broadcast of The United States Steel Hour on ABC radio. Frank Sinatra was the first actor to portray Donald Lam.
Cool and Lam first appeared on television in the January 6, 1955, episode of Climax! based on the debut novel, The Bigger They Come (1939). It starred Art Carney as Donald Lam and Jane Darwell as Bertha Cool and is considered "lost."
A 30-minute pilot program called Cool and Lam was made in 1958 but never became a series. Billy Pearson was cast as Donald Lam and Benay Venuta as Bertha Cool. The pilot was loosely based on Turn On The Heat. One feature of interest is that, a few minutes after the start of the program, Erle Stanley Gardner is shown on the set of Perry Mason's office. He speaks directly to the viewer, introducing the characters, and talking about his pleasure in the casting and his hopes that the pilot will become a series. It is uncertain whether this pilot was ever broadcast and, if so, whether this segment featuring Gardner would have been included, since it pushed the running time of the program to the 30-minute mark and did not allow for commercials.