Callahan's Crosstime Saloon
Spider Robinson
 The bar is run by Mike Callahan. The regulars are welcoming and willing to listen to any visitor's problems, no matter how strange, but do not snoop if a visitor is unwilling to share. Strange and unusual events and visitors turn up with frequency in the stories. Regulars at Callahan's include a talking dog, several extraterrestrials and time travelers, an ethical vampire, a couple of Irish mythological beings, and an obscenity-spewing parrot. The stories make heavy use of puns. Irish whiskeys are the preferred beverage, with Tullamore Dew and Bushmills mentioned in nearly every collection of shorts or novel that references the saloon. The stories make an obvious homage to Fletcher Pratt and L. Sprague de Camp's Tales from Gavagan's Bar and Arthur C. Clarke's Tales from the White Hart. Lady Sally McGee, the madam of a house of excellent repute (and Mike Callahan's wife), stars in Robinson's Callahan's Lady and Lady Slings the Booze. The regulars at Lady Sally's brothel (where the employees are "artists" and the patrons are "clients") insist on the same empathy and humor as those at Callahan's, and they are just as likely to have fantastic backgrounds. Relatedly, nobody in Lady Sally's is forced into anything they are unwilling to do. This is the source of Callahan's Law (also known as the Law of Conservation of Pain and Joy): "Shared pain is lessened; shared joy, increased—thus do we refute entropy." Stated another way: "Just as there are Laws of Conservation of Matter and Energy, so there are in fact Laws of Conservation of Pain and Joy. Neither can ever be created or destroyed. But one can be converted into the other."