The characters of "Lefty" are:

Emperor Alexander I (Pavlovich):

In the story, Alexander visits England and finds himself fascinated by the talents of English artisans. He is accompanied by Don Cossack Platov, who amazes him with his seeming indifference to foreign accomplishments.

When Alexander is presented with the steel flea (or, the nymphosoria) by the English officials, he declares that no artisan in Russia can match their English counterparts in crafting such exquisite inventions. Alexander also orders Platov to pay the Englishmen lavishly for the nymphosoria. Neither Platov nor Alexander reconcile their differences in regards to foreign inventions.

Don Cossack Platov:

Platov serves two emperors in his lifetime: Nicholas I and Alexander I. He accompanies both to England to tour the nation's factories and museums. Each time, he tries to steer his sovereign's attention away from English inventions.

However, he is largely unsuccessful in his efforts. Undeterred, he engages in oneupmanship against his English counterparts. In the story, Platov drags Lefty (one of the Tula artisans) before Emperor Nicholas I to explain the intricacies of his invention.

The English officials:

Throughout the story, the English officials tout the accomplishments of their nation's artisans. They show Alexander inventions such as trench coats for the infantry, muskets, and pistols. In the story, the English officials present Alexander a gift of a steel flea (the nymphosoria) as proof of the superiority of English craftsmanship.

Later, they try to lure Lefty (one of the Tula artisans) to emigrate to England. The English officials promise him a wonderful education, a wife, and a new life. However, Lefty turns them down.

Emperor Nicholas I:

In the story, Nicholas commissions Platov to find Russian artisans who can best their English counterparts' steel flea invention.

The Tula masters:

These Tula artisans make shoes for the nymphosoria. Their invention impresses Nicholas I because the shoes can only be seen by a meagroscope. Lefty is the Tula master Platov brings before Nicholas I. In the story, Platov makes Lefty travel without a "dokyment," or internal Russian passport.

Lefty:

Lefty is one of the three Tula artisans who work on remaking the nymphosoria. While his fellow artisans fashion shoes for the flea, Lefty crafts the nails needed to keep the shoes in place. His daring and outstanding work impresses Nicholas I, who commissions him to deliver the newly improved nymphosoria back to the English.

In the story, he is forced by Platov to travel without an internal Russian passport. Because of this, no one recognizes him after he returns from England.

Lefty is taken from one hospital to another. He is rejected by all of them, as Russian hospitals cannot admit anyone without a passport. In the end, only the Obukhovsky Charity Hospital will take him, and this is only because it primarily welcomes people of "unknown estate." Lefty dies at the hospital before he can apprise Nicholas I about why English weapons are far superior to Russian ones.