Elizabeth Proctor appears for the first time in the play at the beginning of Act II, and we see immediately that there is a tension between her and her husband.
On the surface, the scene is one of domestic peace. John comes home from his work in the fields to the dinner Elizabeth has prepared for him. She comes downstairs after settling their children to sleep and sits at the table with him. However, there is a disharmony between them, which is immediately apparent in their conversation and actions. They talk civilly, but not at all intimately, about the weather, the fields, the boys. She watches him closely as he eats. He lies about the stew being well-seasoned (he added the salt himself). When he goes to kiss her she merely 'receives it'. She responds to a light reminder on his part to bring in flowers as though she had made a major omission.
We see therefore that the interaction between them is not at all close, and their conversation is stilted. We can guess why; we have seen in the first act that John had a dalliance with Abigail, their serving girl. Therefore his relations with his wife are now extremely strained.
John appears to make more of an effort than Elizabeth to ease the atmosphere, making a show of good companionship:
On Sunday let you come with me; we'll walk the farm together; I never see such a load of flowers on the earth.
She doesn't respond to this invitation, but remains guarded, until he's finally compelled to ask if if she's 'sad again'.
At this, all Elizabeth's underlying tension bursts to the surface; and she says what she really wants to say, which is more or less to accuse her husband of going to Salem to see Abigail. She also goes on to inform him that the witchcraft trials are well underway now, with Abigail at the forefront of the accusers. It is the beginning of events which will tragically spiral out of control for both the Proctors, ending with their condemnation, and John's hanging, by the court.