Panic
In a panicked voice, Cliff told Linda to leave the bag alone. If it wasn’t his and it wasn’t hers, then it was more sinister than either of them could have guessed. It was now clear to the couple that the bag was left there by the burglar.
But the thing was that Cliff wasn’t there to protect his wife if the bag was dangerous. He told her to come out of the house, and he’d meet her outside. But his wife’s curiosity would get the better of her.