After chatting with Doc and Firesong that morning, Val felt much more alert and caffeinated, which helped in her latest project- a time delay ignition system to activate a thermite warhead in a controlled fashion. Igniting the stuff was easy- figuring out how to only ignite it when she wanted to was... trickier. Her initial approach had been to use timer devices- which worked well enough. The problem was, it took a book of calculations to have the weapons detonate on, or near, a target. Valence didn't see how crunching numbers in one's head was such a deal breaker, but the brass had insisted, so back to the drawing board she went.
Ideally, an impact trigger would be perfect- provided she could design one that wouldn't go off when the round was fired, but would when it impacted a target. Val had been pondering this for some time- and aside from managing to concoct a harmless foaming agent that could be used to test the ignition system, there wasn't much to show for it. The foam dummy shells at least worked the same way- two inert chemicals mixed together with a catalyzer added in to cause the reaction, which in this case, caused lots and lots of poofy foam instead of thermite. It was good for practicing, but hadn't helped her make a breakthrough.
Nova and Onyx with with her parents in Canterlot for the day, and with Doc and Firesong gone, it was pretty much just her in the lab. Val nudged her classes up her nose with her magic, and got to work. About two hours later, and covered in foam, Valence had devised a system where the force of one impact in the rear of the shell would light the catalyst, and the force of impact would break the chamber that held the lit catalyst. The downside was that the shells would have to be filled with the catalyzer before firing, in order to keep them from going off prematurely. But three of the four dummy shells she tested worked perfectly, while one didn't go off at all. So that was a pretty good success rate, all things considered.
The sound of approaching voices must have meant Doc and Fire were back, maybe even with Mel in tow. Val scribbled down her progress notes, stuffed the notebook into her lab coat pocket, and trotted out to meet her friends.
Val arrived just in time to see Doc show Mel the Zeropaz. "Oh hey, Mel! So good to see you again! I hope you like it, Doc has been busting his flank on it, and suckering the rest of us into helping him," Val said, giggling. "Seriously though, I was more than happy to help out. Anything for a friend," Val said, smiling warmly and wiping a stray tear. She hadn't seen Melody in such a long time.