Okay, I guess.
“Trigger Warning”
A group of very tired miner ponies come to visit Twilight’s castle to ask for her help with a delicate matter: they have been digging a tunnel through a mountain range to irrigate some dry lands, but they got stuck when they reached a rock mantle so hard and dense that they cannot dig though. Twilight quickly agrees to help them and so, she prepares a batch of an absurdly powerful explosive to help them to blast through the obstacle and finish their irrigation tunnel faster.
The explosives are loaded on a special cart intended to keep everything safe, but Twilight also remindes everyone that the explosives will not explode without their detonators, so they are perfecly safe to handle. In fact, they are so safe that she will accompany the miner ponies to teach them about how to assemble, activate and use the explosives once they arrive to their destination. Rainbow Dash offers herself to guard the cart because the adrenaline rush is too much for her to ignore, and Spike decides to go with them because SOMEBODY has to pick up their pieces in case something goes wrong.
So of course, it only takes a couple days of a very quiet traveling until some mountain bandits notice the pony caravan jealously guarding a big cart and so, they run away with it, thinking it’s loaded with riches. Cue the hysterical chase where the bandits take the cart through some extremely bumpy and dangerous roads while the terrified ponies desperately try to catch and stop them before the cart explodes and takes the bandits, ponies, dragon and several mountains with it.
As a running gag, a very irritated Twilight constantly remindes everyone that no, the explosives will not detonate even if the cart is set on fire or falls down a cliff, but everyone are too scared to listen to her and so, the episode is full of anticlimatic situations where the bandits do absurdly dumb and dangerous things with the cart and everyone keep taking cover for a mega explosion that never happens.