Dangerous Liaisons by Pierre Choderlos de Laclos

You saw how we were disappointed yesterday. I could not find an opportunity to deliver you the letter I had the whole day; and I don't know whether I shall be more successful this day. I am afraid of hurting you by my over zeal; and should never forgive myself, if by my imprudence you should suffer; that would make my friend distracted, and you miserable. Yet I am not insensible to a lover's impatience. I feel how painful it is in your situation to experience delay in the only consolation you are capable of receiving at this time. By dint of thinking on means to remove obstacles, I have found one that will be pretty easy if you will but give your assistance.

I think I remarked, the key of your chamber door, that opens into the gallery, hangs always upon your mamma's chimneypiece. Everything would become easy, if we were once in possession of that key; but if it is not practicable, I can procure another exactly similar, which will answer the purpose: it will be sufficient I should have the key for an hour or two. You can easily find an opportunity of taking it; and that it may not be missed, you have one belonging to me, which resembles it pretty much, and the difference won't be perceived unless it is tried, which I don't think will be attempted. You must only take care to tie a blue ribbon to it, like the one that is to your own.