It was a beautiful day for a Canterlot Wedding. The Mane Seven - less Twilight who was trappend in the cave - were standing at attention as bridesmaids to Cadence and Shining Armor. Cadence was actually Queen Chrysalis in disguise, unbeknownst to all of them... well most of them. The pastor said
"If anypony has any reason that these two should not be wed, speak now or forever hold your grace." Cassandra said,
"I've got your reason right HERE!" In an instant, she turned and smashed the impostor with her hind hooves. Chrysalis flew back and crashed through a stained glass window. Princess Celestia tried to hold the Changeling queen back, but it was hopeless and and she fell to the ground. The changelings came in and disguised themselves as ponies. But led by Cassandra's bravery they fought them back, and the Changeling army was defeated. The crowd cheered, they had saved Equestria, with Applejack as the only casualty. They weren't sure if they should hold the wedding given the circumstance. Then Twilight spoke up,
"We should go ahead as planned. Applejack wouldn't have wanted to be a buzzkill."
"Twilight!" chided Cassandra. She couldn't believe Twilight sometimes, that filly had all the book smarts in the world, but no idea how to behave in public. She had a point though. So they held the wedding and Cassandra sang "love is in bloom."
The following months were somber becuase they'd lost their friend, but at the same time unburdening because they didn't have to pretend to like Applejack's apple-flavored desserts anymore.