Can I delete individual messages in a Gmail thread?

First off, did you realize that you can actually turn off threading in Gmail now? Used to be that wasn’t an option but in the last year or two the Google Mail team must have heard a ton of requests and finally gave us the option. How do you do it? Go to General Settings and search for “Conversation View”, then disable it. Done.
Assuming you want to stick with threading, um, I mean conversation view, it turns out that there’s also a way you can remove individual messages from a conversation thread, and there’s even a way you can mark an entire thread as “read” (check the box adjacent to the thread in the mailbox view, then click the “Mark as Read” button that appears).
But let’s stay focused!
Here’s a conversation thread between our main video game and computer game writer, Zach Comm, and myself, discussing iOS application roundups:

As you can see, it’s a typical conversational back-and-forth. But what if Zach’s second message turned out to be a completely off-topic communication, one that I just want to remove from the thread entirely, but otherwise I still want all the messages after that one?
Sorry, Zach, here’s how we’d remove it…
First step is to expand the message in question, which is most easily done by simply clicking on the fragment of the first sentence shown. The message expands:

On the right, just adjacent to the date on that specific message, note the leftward pointing arrow. Next to it is a downward pointing triangle. Click on it…

You can guess, “Delete this message” is what you seek to axe a specific message in a conversation thread. Not much happens, you just suddenly see the thread without that message. Look closely at the top, however, and there’s a short-lived status message:

Meanwhile, close up the thread and the deleted message has vanished:

That’s all there is to it. And one of the other options on the individual message-related menu is useful to notice: “Mark Unread from Here”. Useful if you browse mail on your mobile device but want to have specific messages go back to “unread” when you’re at your desk.