The son of Sir George Croft of Crofts Limited, a competitor of Birling and Company, he is at the Birling residence to celebrate his recent engagement to Sheila Birling. Gerald is revealed to have known Eva and installed her as his mistress, becoming "the most important person in her life", before ending the relationship. After the revelation of his affair, he is not blamed as heavily as the other characters (Sheila commends him for his honesty and for initially showing Eva compassion, even though he is shown as cowardly and thoughtless for taking advantage of a vulnerable woman). He is caused to confess as soon as he shouts out in shock at hearing the name he had known Eva by (Daisy Renton), allowing the Inspector to investigate Gerald's involvement in Eva's life. Gerald thinks that Goole is not a police inspector, that the family may not all be referring to the same woman and that there may not be a body. Initially he appears to be correct, and does not think the Birlings have anything to feel ashamed of or worry about. He seems excited at the prospect of discovering the 'fake' Inspector and seems almost desperate for others to believe him.
Gerald understands that his affair will now be revealed to the family. He knows it will hurt Sheila, and initially he lashes out at her, believing Sheila wants to see him suffer as she has suffered. Gerald does have a hard time understanding that Sheila will be more accepting of the affair once she has heard all about it from his own mouth. For Sheila admits, at the end of this section, that knowing or guessing only a bit of the story is harder than find out about it all at once. This, the audience will later learn, is uncharacteristic of Gerald, who appears a kind and conscientious person. Even the Inspector agrees, later in the play, that Gerald’s behavior to Eva/Daisy has not been overly cruel. Their relationship was illicit, and Gerald was dating Sheila and lying to her while it was ongoing. But Gerald was not cruel to Eva/Daisy, and he appears to have genuinely wanted to help her.