"You're the man from the past, aren't you?" asked the man entering the room with the water. A small table arose from the floor near the center of the room, where a helmeted figure stood. "Plain water, in case you're thirsty," he said, placing the pitcher and glass on the new surface.
"Yes," said the man, never looking away from the wall on which many figures were projected. They bore the knowledge of the synthesis of a serum that could cure his ailing - and, at the moment, long-dead - wife, "I am the man from the past. I'm done here, though, since I've finished committing this data to memory, so I'll be going back there soon. That's not why the water is here, by the way."
The servant grew slightly nervous at this. "Well, that's what I was told."
"Something on your person when you entered this room was meant to release nanobots into the air, since I scanned it upon entering, but might not be bothered to do so every time that the door is opened. Your boss was likely frustrated that my helm bears a Faraday cage. However, they won't be able to follow me, for the same reason that it would be fruitless to drink that water, despite my thirst: My transporter is quantum-bound to the particles in my body." With that, he disappeared.
"A craft just launched from the next system over, sir, heading rimward, but 44.7286 off the galactic plane," said a cog of a man stationed at a control panel. "It's topped out at 0.99926c, though. It looks like it's got some outdated stealth tech."
"Send our fastest ship after it now," said his boss. "We'll catch up, though it'll be a while, due to the delay."
"Ours has departed with the most proximate crew available. They're at speed. They should catch up in about three years, give or take for possible evasive maneuvers."
"I expect the entire galaxy to be searched thoroughly," said the man in the pointless throne. "You don't understand how valuable this knowledge is. The man from the past knows the secret to bi-directional time travel. I want every piece of his decoy craft examined meticulously for any trace of his true destination."
"You don't yet control the whole galaxy," advised his minion. "Your rivals will take offense at your probing their territory so thoroughly."
"Let them," decried the would-be ruler of the galaxy. "Once I have the secret to time-travel, I can shape the galaxy to my very needs."
I would go on about what else happened, but their entire timeline ceased to be once the man from the past saved his wife.
Author's note: This bit of story was inspired by the song The Time Machine by The Cog is Dead. I worked out the details of creating, using, and concealing a relativistic bi-directional time machine, though they unfortunately didn't emerge during the narrative.