The word 'shift' has been reminding me of something, couldn't quite grasp it, and I just remembered what it was.
There's a Star Trek Novel, FEDERATION (probably the best one ever written), that traps Kirk Crew on the 1701 and the Picard Crew on the 1701-D in a black hole below the event horizon at the same time. They're not allowed to communicate -- Federation rules against transmitting information from the future to the past. They're both there on a mission to rescue Zephram Cochrane's shuttle, where he's trapped with the Companion.
Anyway -- they both figure out there are two moves open to them, one, to escape themselves and strand the other ship there forever, or, two, to take a chance that Spock and Data have both spotted the same one-shot chance of catching a triple wave, riding it together and slingshotting each other to the right place in space-time. There is no other information. All they can do is trust that the same ideals drive each other. Picard has his doubts that Kirk was driven by those ideals, and thinks his cowboy heroism is perfectly capable of saving his own crew and stranding a ship with people he's never met. But he can't remember...is this when the Enterprise was destroyed. Their computers are down, so there's no way they can find out. All the can do is make his best guest. What he doesn't know is that Kirk figured out the other ship is also the Enterprise, and it affirms for him that ideals of the Federation are alive 100 years later, and he knows that saving both ships is the right thing to do. Kirk is compelled by morality; and Picard is compelled by his sense of duty.
THE POINT IS (thank you), they start off--they scoop up the shuttlecraft they came there to rescue, balance it there between them, it's going back with Kirk--then they realize their calculations were off and there is only one way to correct them...and they SHIFT the shuttlecraft over to Picard's Enterprise, to go with him into the future.
It made me think of shifting elements in order to arrive at a solution, once things have gone south with the original plan.
(Side note: best thing about the novel: in the rescue attempts both have to engage in before they go into the black hole, Picard has to change the rules of the game to win, whereas Kirk has to abandon his cowboy heroism and rely on the skills of each of his crew to accomplish a complicated maneuver in ensemble. Best done role reversal I've ever seen in the genre. I read this thing 20 years ago and it's stayed with me ever since.)