1. Ludwig van Beethoven

Given a hearing aid, Beethoven hears some of his most famous compositions for the first time.

3. Thomas Edison

Unsatisfied with the quality of his phonograph recording, Edison insists on recording a new version in a modern studio.

4. Mary Wollstonecraft

Mary's arrival gives Dan a chance to express his feminism, but he is irritated by Mary's stern demeanor. Meanwhile, it is Spencer's birthday.

5. William Shakespeare

Shakespeare is unimpressed by Community, preferring the bawdy comedy film Dirty Grandpa.

6. Idi Amin

Amin's arrival fulfills Dan's desire for ethnic diversity, until he takes the office hostage.

7. Betsy Ross

Betsy's racism discomforts Dan until they broach the subject of Bernie Sanders.

8. Amelia Earhart

Amelia is disappointed with her legacy of getting lost, and sets out to prove that she is indeed still alive.

9. Sigmund Freud

Freud arrives just in time, as Spencer refuses to use catchphrases written for him by Dan.

10. Edgar Allan Poe

Poe undermines Dan's need to impress a History Channel executive, who falls for Poe. Dan and Spencer attempt to influence their date to secure an additional run of episodes.

11. Buddha

The Buddha participates in a series of product placements, making Dan feel guilty.

12. John Wilkes Booth

Booth emphasizes his skills as an actor rather than his notoriety as the assassin of Abraham Lincoln.

13. Ada Lovelace

After they bond over their shared love of coding, Ada convinces Spencer to convert his body to code and join her in virtual reality.

14. John F. Kennedy

Kennedy is accidentally transported along with a spider, creating an additional half-Kennedy-half-spider being which cocoons the crew.

15. Harry S. Truman

Dan takes Truman to a gay bar to teach him about gay rights and desperately pander to LGBT critics.