"Oh, relax," said Beckett. "'Tis but a flesh wound." She then got up to beat up her attacker.
She smacked him around for about a minute.
"Who wanted to kill my mommy?" she demanded.
"They did," said the shooter, pointing to Ryan and Esposito.
"No!" said Beckett. "It can't be!"
"Yes!" said Esposito. "WE'RE THE REAL BAD GUYS! AHAHAHAHAHAHAHAHA!"
"But why?"
A long minute passed.
"Come to think of it," said Ryan, "why did we do it?"
"Beats me," said Esposito.
Beckett knocked their heads together. "I am so mad at you right now!" she said.
"Too bad," said Ryan, "for we have backup!"
"What?"
Castle looked on in horror has his poker buddies showed up, converted into battle cyborgs.
"Guys, guys, guys," said Castle, "you of all people should know what a lame plot twist this is."
"TROPES ARE NOT BAD!" yelled one of the writers, as he fired a plasma cannon at Castle and Beckett, who just barely dodged.
Esposito used his newly-discovered magic to raise Montgomery as a zombie, which then merged with the bad guys to form Voltron.
"Oh snap!" said Castle. "this would be a great twist for my-"
"Don't even think about it," said Beckett.
"I have an idea." Castle walked over to Voltron and pressed its off button, turning it back into the people who formed it.
"An off button!" said one of the writers. "What were you thinking?"
"Tie them up, Castle," said Beckett. She then put Montgomery back in his coffin, then they finished his funeral. After that, they took all the bad guys to the police station.
And so the mystery of Mrs. Beckett's death was solved once and for all.
Okay, not really, since this isn't canon.
THE END