Bertha Cool is a fictional American detective created by Erle Stanley Gardner under his penname "A. A. Fair." Overweight (275 pounds) and in her 60s, Cool opened her own detective agency in 1936 after her husband Henry died. In the first book about her, The Bigger They Come (1939; British: Lam to the Slaughter), she hired Donald Lam, a disbarred lawyer only 5' 6" tall (125 pounds), and the duo appeared in more than two dozen books.
He begins his adventures as the employee of BerthaCool, a stout widow in her 60s who started their detective agency in 1936.
Donald eventually became such a moneymaker for Bertha that she relented when he put the pressure on her for a full partnership in "Double or Quits." In a case involving double indemnity in the event of death by accidental menas, Donald knew the legal difference between it and accidental death.
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.
Bertha is a "mountain of a woman" with diamonds on her fingers and a nose for the client's cash.
Bertha maintains her weight loss from Spill the Jackpot, Elsie Brand is revealed to have a private life very different from her professional life and Donald pretends to be involved with the girl as opposed to being involved with the girl.
While Bertha watches the bottom line, drinks Planter's Punches and goes native in a muu-muu, Donald finds himself closely aligned with the widow who is suspected of not being able to wait for her business relationship to terminate in a natural course and her friend, another open-minded young golddigger.