How do "episodes" in a fugue typically modulate?

Episodes in a fugue serve as transitional sections that often connect statements of the main subject or theme. During these sections, the composer typically employs sequences to introduce new material while still maintaining a musical connection to the subject. Sequences allow for the manipulation of melodic and harmonic content, creating motion away from the original key before returning to it or moving to a different key.

This technique effectively provides contrast and development within the structure of the fugue, facilitating modulation to different keys while ensuring that the episode remains cohesive with the overall texture of the piece. Hence, the use of sequences is central to how episodes function and modulate within the context of a fugue.