Multiple trend lines on same line graph

Excel beginner here.

I have a single column of data that I'm using to create a line graph. It tracks the word count of different sections in a novel. The novel is broken into four movements (Setup, Buildup, Climax, and Denouement), but I'm noting this manually outside the graph.

I'm trying to add trend lines so I can show how section length trends within each of the four movements. Obviously I could just break the data down by movement and have four separate graphs, but I want to have them all of on the same graph to save space.

I watched this

YouTube + watch?v=m6OazqcAbpo (new user, won't let me post links yet)

and tried dragging down the highlighted box, but it just added the data for Buildup to the series of data for Setup instead of keeping them as two separate series.

I tried putting them in different columns, but that just gave me multiple overlapping lines.

Ideally, I'd have one large line graph with four separate trend lines over the four different movements. Any ideas?