Fixing this thing would require a minimum of three events, all easier said than done.

1. •I needed to get out of the hospital.
   

2. •I needed to time travel again.
   

3. •I needed to change my sister and myself back to my sister and myself.
   

    In my mind, the best way to accomplish all of the above would be for older me to go back and stop me from getting to Dad.  Three birds with one stone as they say.

    “You’re not thinking fourth dimensionally,” he said after I outlined my plan.  “I can’t go back to stop you because you’ve already been there.  I thought you understood this part.  Only one trip, remember?  You were there for so long the window is essentially closed for me.”

    “You could go back to before I even got there and warn Dad not to believe me when I show up,” I argued back.

    “Think about it.  Even if I could convince him to ignore you, you’d just jump back even further to make it work.  And if you landed on a date I had already been to, you’d negate my trip.”

    “Won’t I be blocked from going anywhere you’ve already been?”

    He glared at me with a look that evoked a professor who catches a student not paying attention in class.  “If you make a trip at a younger age than I was when I made it, then I never made it because you just prevented yourself from making it when you grow up to become me.  It’s not the actual order we make the trips in, but the order relative to our ages.”

    “But if this version of me never made the trip, then I never did visit Dad.  But if he didn’t visit Dad, I’d still be me.  One event causes the other.  We’re in a paradox, aren’t we?”

    Older me looked uneasy as he answered.  “I don’t know.  Theoretically we should be, but also theoretically if this were a paradox we should cease to exist.”

    “You say correlation is not causation?”

    “Perhaps,” he said, still lost in his thoughts.  “Unless it means that we still will visit your father.  Or at least that we still can.”

    “If I can’t do it since I’m trapped here, and you can’t do it since I already have, where does that leave us?  It should already be over.  There’s something happening here.”

    He shook his head.  “You’re right.  But what it is ain’t exactly clear.  As soon as you returned to your present that should have been the end of everything, but I’m protected from paradox since I haven’t been back to my present.  And since I’m you, maybe we’re both safe.”

    At least that was a relief.  Changing gears, I had another idea.  “What if you gave me a booster shot?  Then I’d be able to blink back to Dad and prevent this place from happening.”

    The look from older me was now solemn. “I don’t have the syringe with me,” he said with neither smile nor nod.

    “What happened to it?”

    “I used it on you.”

    “But you showed it to me after...”

    Again he was becoming impatient.  “Afterwards for you, but before for me.  It’s gone.”

    This new theory of relativity was getting complicated, not to mention confusing.

    “So why don’t you go back and get another one, and then meet me here tomorrow for my shot?”

    Professor look again.  “If I go back to my present, I’ll become future you, meaning future you who can’t travel in time.  Not to mention the fact that I’d likely unlock the paradox you’ve already caused with your father.”

    “But you said you haven’t been back, so you don’t have to go all the way.  Can’t you think of a time when you still had it, then meet me here?”

    He would have hit me with a ruler if he had one.

    “It doesn’t work that way.  It’s gone.  Accept it and move on.”

    Although the time travel rules and theories still confused me, I was able to stop grasping at straws and understand his plan.  And I didn’t like it one bit.

    “You want me to just wait it out, hoping I have a chance to steal a syringe like you did?  They don’t even have that kind of syringe yet.”

    Nod, but no smile.

    “Are you even serious?”

    The door suddenly opened.  It was the head doctor.

    “Who are you talking to?”

    Older me shook his head in warning.  I didn’t know what he was so worried about, as I could answer truthfully without attracting suspicion.  “I’m just talking to myself again.”

    He didn’t buy it.  “I know what’s going on, and I know that this experiment is going to be successful with or without your help.  With your help will be better for both of us.  Are you going to cooperate or not?”

    My first instinct was to assume he was bluffing.

    “Tell me what’s going on and I’ll tell you if I’ll help.”

    The doctor took a long look at me with pursed lips.  It seemed he couldn’t quite get a read on me, but eventually decided there was nothing left to lose since I was his captive.

    “I believe you when you say you were talking to yourself.  My primary interest is in which self you were talking to, and how that came to pass.”

    Older me gave a confused shrug while the doctor waited for a response from me.  Getting none, he continued.

    “A thoughtful man may have an internal debate with himself inside his own head.  An angry man may speak to himself aloud out of frustration.  A crazy man may speak to himself aloud for attention.  But you were talking differently.  You were having a normal, logical discussion.  Don’t try to hide it, I could tell.  Why do you think I let the conversation go on for so long?”

    I supposed he was smarter than he looked.  But he still hadn’t explained what he wanted.

    “I’m not quite understanding how I can be helpful,” I said, trying not to look at my other self.  A plan had come to me that he wouldn’t approve of, and I couldn’t risk his presence being uncovered or his altruism knocking me off track.  With one hand in my pocket, I groped to verify the contents.  Wallet, keys, phone.  Good thing this wasn’t airport security.

    “What were you talking about?  How can we make it happen?”

    “I’ll confess,” I said, trying to sound as remorseful as possible.

    “Excellent.  I’m listening.”

    “You caught me trying to plan my escape.  I called my brother-in-law on my cellphone.  His name is Nelson, and he is going to try to break me out tomorrow.”

    Nelson wasn’t actually my brother-in-law anymore, but that wasn’t really important now.

    The doctor was taken off guard by both my answer and the incompetence of his staff.  “They let you keep your phone?”

    Luckily enough they had.  Nobody bothered to search me.  That was remedied quickly, as the doctor snapped his fingers to summon his henchmen.  They confiscated everything I had, giving me a rather rough pat down for good measure.  Convinced I didn’t have anything else on me, each one grabbed an arm and awaited further orders.

    “Take him back to the room, and send someone to pick up this Nelson character.  Between the two of them we’ll get our answers.”