The real story
Twain was born in 1835, just after the comet passed. He said he came in with it and expected to go out with it. He died in April 1910, a day after the comet's closest approach to the Sun.
Edmond Halley was the first to realise the comets seen in 1531, 1607 and 1682 were the same object, and predicted it would return in 1758. He didn't live to see it, but it came back on schedule. Its nucleus is a lumpy, dark lump of ice and dust about 15 km long. In late 2023 it reached the farthest point of its orbit and turned around. Next visit: 2061.