Reluctantly he handed over the key
Here's my take:
Reluctantly he handed over the key. “Are you sure you want to know what’s on the other side of that door? It hasn’t been opened for centuries.”
She nodded grimly. “This tomb holds my ancestors. That means it might hold the answers to saving my son. I don’t care if there are demons on the other side of that door, for him, I’ll face them.”
She didn’t know he loved her. It didn’t matter—for her, he would face demons, too. Or whatever else might be waiting for them.
Raising his holy water, he nodded as she turned the key.
Now see how everyone else did it!