Remember, chapter 18 and 19 happen at the same time.

Jeremy opened his eyes and looked around. He was in the hospital, but everything was bright and it was extremely quiet.
“Hello, Jeremy”
Jeremy turned around and couldn’t believe what he saw. of who he saw.
“You seem to be a little shaken. What’s wrong?”
“Am I dead again?” Jeremy asked.
“No, don’t worry. You’re unconscious. Though u almost died. Your friend Bonnie tried to kill u again”
“Do u have any idea how contradicting that sentence sounded? Friend and kill are two words that don’t fit together”
“This had to happen. u had to be unconscious to understand what is going on and how u can stop it. It also shows u how to send the ghosts back. That’s why Vicky and Anna tried to keep u awake, so u wouldn’t figure out. It was pretty reckless of them”
She walked to him and reached out her hand. “Are u ready for it?”
Jeremy took a deep breath and nodded.
“Show me everything” he zei and he accepted Jenna’s hand.
The room disappeared and they were standing volgende to Damon and Elena who were talking to Bonnie.
“I can’t believe you’re asking me this, Elena. I’m going against all of my believes if I do this. Last time I helped them I almost lost Jeremy! I won’t go through that again!” she zei upset.
“I don’t get what’s so weird about this scene” Jeremy frowned. “She’s acting normal”
“Look at the ground” Jenna pointed. Jeremy looked and saw that instead of one shadow, Bonnie seemed to have several, each moving on their own.
“This is your idea, isn’t it? Of course it is. Only u can come up with something that tactless. u really have no shame-whoah”
The shadows moved around Bonnie and went inside her.
Bonnie lost her balance and Damon caught her door her shoulders, pushing her back on her feet.
Jeremy looked back at Jenna. “She’s possessed” he zei soft. “She can’t help it”
Jenna shook her head. “It’s not like that, Jeremy” she zei bitter and sad. “It’s not like that at all"
She took his hand. “Come on, there’s meer u need to see”