[The fear that it could happen again is exactly what's paralyzing Richard right now and preventing him from promising that he won't hurt her anymore. The last thing he wants is for her to spend her time in Luceti frightened that someday he'll try to inflict harm on her again.]
I won't come near you again, so... you don't have to worry.
[action]
I won't come near you again, so... you don't have to worry.