Complex sentence: The only character Stebbins truly interacts with is Ray Garraty, and their conversations allude to "Alice in Wonderland" as Garraty relates him to the Caterpillar.
Split into simpler sentences: The only character Stebbins truly interacts with is Ray Garraty. In one conversation, Garraty alludes to "Alice in Wonderland", likening Stebbins to the Caterpillar.