Suddenly, he understood! Newton insisted that everything must have an equal and opposite reaction. There must therefore be an inverse relativity, where if (e=mc2 divided by k1) and (-e=mc2 divided by k2), 0≤k1≤1, 0≤k2≤1 and k1+k2=1. This would allow selective time travel, so all cancers, say, could be treated by rolling back to their beginnings.
Now… how to explain that to lesser beings?
He began in the usual way: he climbed off his owner’s lap and onto the keyboard.