(Yes, I still lurk here.  :-) )

I need help with a sentence.  I think I have the tense wrong, but I'm not
certain.  Here is the sentence in question.  For dramatic effect, it has
been split into a sentence and a fragment, with the fragment forming its
own paragraph:

        Now, her darling baby boy had returned, all grown up.
        And she might have to kill him.

It's the fragment that's bothering me.  I think I have the verb tense
wrong, but I can't think of any other way to write it.  I tried a couple of
other forms that were more exact in terms of tense agreement...

        And she had to consider the possibility that she would have to kill
him.
        And it was possible that she would have to kill him.

I gagged on both of these and tossed them.  I want something abrupt,
sudden, stabbing.  These meander too much.  Those who read my work may know
that I'm almost anal-retentive when it comes to narrative flow.  I don't
just want a description, I want it to have a specific feel.

The problem is the tense agreement, "had returned" versus "might have to
kill".  Any opinions would be appreciated, even if you just think the
original version is fine.

------RM