"...Few Enough Of Us Around..."

In Poul Anderson's The Boat Of A Million Years, Hanno follows every rumor or clue that might lead him to a fellow immortal. When at last he succeeds, elaborate circumlocutions are necessary before the truth can be divulged. Even then, caution and suspicion keep them apart for nearly another millennium. At last, Hanno convenes a small group.

However, after many centuries of outliving mortals, might two immortals not be able to recognize each other at a glance? In Neil Gaiman's The Sandman: The Wake, Hob Gadling travels as the single passenger on a cargo-carrying tall ship which he discretely owns. Only the captain knows that the passenger is also the owner. When a stowaway is apprehended, the captain would put him off at Aden. However, Gadling has a word and the Indian gentleman's passage is paid. Gadling has instantly recognized a fellow immortal.

"There's few enough of us around. Least we can do is watch out for each other."
-Neil Gaiman, The Sandman: The Wake (New York, 1994), p. 88.

A good philosophy - to be extended to all of humanity, of course, especially to the unfortunate mortals...