Looking at your screenshot, you have a couple of discretionary line breaks after the second date which are a different point size from the text. "What's *that* got to do with it?" I hear you cry. The answer is that in InDesign, leading is a *character* attribute rather than a *paragraph* attribute. One character with larger-than-the-rest leading will affect the entire line.

Here's InDesign's hidden character secret: any character in InDesign, including a number of special characters that are normally hidden, has formatting applied, including point size and leading.

The paragraph mark is the even-more-special character. It stores the formatting for an entire paragraph *and* its own formatting as a character. If you reduce the point size of some text by highlighting it and changing in the Character Panel, but you *haven't selected the paragraph mark* (a very easy mistake to make), the visible text will change but the leading on the last line won't. Because leading is a character attribute, the whole last line will retain the larger leading value of that hidden paragraph mark. (That's why one of the telltale signs of a layout created in InDesign is extra leading on the last line of a paragraph.)

The same applies to other hidden characters, and to non-printing characters such as spaces. A 10/12 line with a 12/14.4 space somewhere in it will use a leading value of 14.4.

Whenever you have baffling line spacing issues, select ALL the text *including the hidden paragraph mark just after the last visible character* and explicitly set the point size and/or leading (which will be blank in the Character Panel, indicating that multiple values have been selected).

In `Preferences > Type` you can turn this character by character behavior off by checking `Apply leading to entire paragraphs`, in which case InDesign will override the character leading and use the value stored in the paragraph mark for the whole paragraph.