When you started working with John Winchester on hunts, you knew there was something crazy about him. But a lot of hunters are crazy, so you've never thought twice about it.

 John is the kind of man you figured would prefer working alone, and you get the feeling he does. But sometimes, he's willing to work on cases with other hunters, mainly you. Whenever you find a case to get working on, you almost always get in touch with John to let him know and see if he wants to join you. Whether or not the two of you go hunting together usually depends on what John's up to. He has two sons, Dean and Sam, and they apparently tend to give him a lot of trouble every now and then.

 There's an occasion when you happen to hear about a vampire nest in Tennessee. You don't know what John's up to right now, but you figure you'll call him and see if he want to join you.

 The phone rings for a while, and almost goes to voicemail before John answers it.

 "What is it, Y/N?" he asks.

 "Just heard about a vampire nest in Tennessee," you say. "I'm gonna head down there and check it out. You game?" 

 He sighs. "No. I'm sorry, Y/N. I can't this time."

 "Oh. You working another case?"

 "Yeah. Something like that."

 "Okay. Um, so what is it? Anything I know how to wrangle?"

 "No. Honestly, I'm not certain yet how I'm going to wrangle it. It's a demon."

 "A demon," you repeat. "Do an exorcism, then."

 "I don't think it'll be that simple. This demon...he's different."

 "Okay. John, could you maybe elaborate a little more?"

 "I shouldn't," he says. "I've been travelling alone on this one. I had to ditch Dean. I left my journal for him to find, but he's probably running around looking for me, anyway."

 Something isn't right. John doesn't sound like his usual self it all. Whatever he's hunting has to be something bad if he would leave Dean out of it entirely.

 "John, where are you?" you ask. "I'll come to you, and you can tell me what's going on here, okay?"

 "No, I can't. This...it's the thing that killed Mary, Y/N. This is something I have to do alone."

 "No, John, you don't. You come see me, then. I'm at-"

 "I told you I can't! I'm sorry."

 "John, don't you dare hang up the phone! Come on, just-"

 You stop when you hear the dial tone. He hung up on you. You slam the phone down on the desk.

 What is wrong with that man? Yes, all hunters die at some point, usually from a very violent death, but this sounds like definite suicide.

 You get in touch with another hunter to tell them about the vampire nest, and then you pack up your stuff and leave. Just because John doesn't want help doesn't mean he won't need it. If you can find him, you could always find a way to be useful.