This is tenebrous. But to obey.

Though he slay me, yet will I hope in him; ...

Dumbledore drew himself up to his full height. 'I take you with me on one condition: that you obey any command I might give you at once, and without question.' 'Of course.' 'Be sure to understand me, Harry, I mean that you must follow even such orders as "run", "hide" or "go back". Do I have your word?' 'I -- yes, of course.' 'If I tell you to hide, you will do so?' 'Yes.' 'If I tell you to flee, you will obey?' 'Yes.' 'If I tell you to leave me, and save yourself, you will do as I tell you?' 'I --' 'Harry?' They looked at each other for a moment. 'Yes, sir.' 'Very good. Then I wish you to go and fetch your Cloak and meet me in the Entrance Hall in five minutes' time.' Harry Potter and the Half-blood Prince, 2005, Bloomsbury, JK Rowling.

... being sure of what we hope for and certain of what we do not see.