When does karna decide that it is safe to sleep in the house with the big gray dog?

Karna decides it is safe to sleep in the house with the big gray dog after observing the dog's calm demeanor and gentle behavior over time. He recognizes that the dog is protective rather than aggressive, creating a sense of trust. This gradual bonding allows Karna to feel secure enough to rest peacefully in the same space. Ultimately, it’s the dog’s loyalty and affection that reassure him of his safety.