Glimpse is useful for putting your skills back in the deck for practice makes perfect, and drawing cards again for the dream serum. You can also put your research cards back in, if you threw them during upkeep instead of discovered them during search. If you play this as Harvey, whose deck this came in, it automatically draws you two cards, while letting you put things in your deck that you can’t afford and hopefully getting things that will help you now. Combine with calling in favors to replace your damaged Miskatonic friends. Or try and draw your weakness while someone has Delay the inevitable or dark insight ready.
Plus, even if you have the perfect hand, two book icons will always be useful as seeker.