John B. McLemore, a profanely outspoken, brilliant and troubled restorer of antique clocks, emerged a national figure in 2017 with the podcast “S-Town.” As a horologist — a repairer of devices that measure time — he restored intricate and rare pieces in a workshop at his family homestead in rural western Alabama.

But that was just part of the story.

In short order, “S-Town” hit 40 million downloads, and has since surpassed 100 million, making it among the most downloaded podcasts.

For those who missed this unusual tale, there will be no major spoilers here. It’s enough to say that McLemore, and many in his orbit, were vaulted from obscurity to sometimes painful visibility.

(Tyler Goodson, a prominent character in the podcast, was killed in a police shootout in December. Jeff Dodson, the mayor of Woodstock, the hamlet where “S-Town” takes place, said he hasn’t received an update on the police investigation of the shooting.)

Before “S-Town,” McLemore was known to collectors of rare clocks, earning fame as an unlikely genius who could diagnose mechanical trouble and revive one-of-a-kind antique timepieces.

One of those collectors, William R. Tatum, was close to “John B.,” as friends called him. Tatum — referred to only as Bill in the podcast — entrusted McLemore with many of his prized clocks. An exhibition of 34 of those pieces, all restored by McLemore, runs through April 30 at the National Watch & Clock Museum in Columbia, Pa.