IF you were not in the library but in the cutout then you have to ask yourself (and from your post you did not): Do I have a play?
What constitutes a play? Fielder -- Runner ----- and THE BALL.
Missing one of the three (Ball) ... no play and follow the advice of justanotherblue and start drifting home (I'm going home!!!). Then if you have the three elements stated above, you get the best angle possible and call him OUT!