Please hold down the POWER BUTTON for 20 seconds until your Nook restarts. After it restarts, try downloading the books again.
If that does not work, please reply back otherwise if you can take a minute and use the rating system to rate our session as 3 stars or higher and press Submit so I am credited with helping you.
Did you connect the Nook back to Wi-Fi when you came home?
Do you receive any error messages?
What does not open? The book?