In Roald Dahl's "Lamb to the Slaughter," how does Patrick treat Mary and what is the bad news that he gives her?
In "Lamb to the Slaughter," we know very little about the dynamics of Patrick and Mary's relationship with the exception of her complete devotion to his needs. She takes care of him, cooks and fetches drinks for him, and appears to love him very deeply. In contrast, in the middle of the story, Patrick returns home from work and delivers some bad news to Mary. Dahl does not reveal the details of this bad news to the reader, but it is clear Patrick wants to end the marriage and seeks a divorce.
The fact that it has played on his mind for some time ("I've thought about it a good deal") and that he intends to provide for her financially suggests Patrick has some consideration for Mary, though not enough to save their marriage. It is also worth noting that Patrick's overriding concern is to protect his professional integrity, as he makes clear to Mary when he says,
But there really shouldn't be any problem. I hope not, in any case. It wouldn't be very good for my job.
This suggests Patrick is less concerned about Mary's feelings than his reputation, and this contributes directly to his murder.