Read it through once

The locale being thus determined, I had now to introduce the bird—and the thought of introducing him through the window was inevitable. The idea of making the lover suppose, in the first instance, that the flapping of the wings of the bird against the shutter is a “tapping” at the door, originated in a wish to increase, by prolonging, the reader’s curiosity, and in a desire to admit the incidental effect arising from the lover’s throwing open the door, finding all dark, and thence adopting the half-fancy that it was the spirit of his mistress that knocked.