Thanks, RoboColum, but my issue is the opposite, i.e.
where I have SHIFT+ENTER at the end of the first two lines, but I want the TOC to show
Prologue: Tuesday morning 1830
I don't think there is anyway around this. The TOC is built using the paragraph tags you use. If there is a tag spread over three lines, it is duplicated in the TOC. I think you will have to manually edit the TOC after you update the book.
Don't use hard returns. Anchor an empty Anchored Frame frame at that heading, Run Into Para, from Right, height equivalent to 3 heading text lines.
Put a non-breaking space between Tuesday and morning, to keep them on the same line (Ctrl+spacebar).
Grab the left edge of the AF with the graphics tool and drag it left it to squeeze the heading left until it flows as you desire for on-page appearance. The TOC entry will still be one line.
I can think of several other ways to accomplish this, but the RRI frame technique is by far the easiest, and the most comprehensible to future document stewards.