The enhancement of extraordinary powers naturally can't be rushed, as countless novels, movies, and other media have repeatedly mentioned how bad things can get if it's not allowed to happen naturally.
More importantly, at a time when all the preliminary conditions aren't met, forcibly enhancing extraordinary powers and actively seeking death are hardly different.
So, after coming down from the airplane, Leonard set those things aside for the moment and prepared to attend some important social events at the end of the year in London.
These social events were the kind that simply couldn't be avoided. After all, given their current work, they could decline most social events without affecting relationships, but the remaining ones were must-attend affairs.
Luckily, the remaining ones were relatively fruitful gatherings, so these events had some value and could pique the interest of Leonard and others.
