Does this last sentence sound familiar?

The End.

It's not "And they lived happily ever after," but an abrupt end that leaves your readers thinking about the future of your characters. It might be the closed end that finishes your characters' lives forever. In any case, it's an end, so how will you begin it?

It's time for you to work out a story. Write an outline, or a summary of your novel. Talk about the major characters, their motivations, their back stories, their wants and needs. Describe them if you can. Talk about how they deal with their problems, and then, bring a problem hurtling into their lives. Talk about how they pull through it. Add a problem if you like; add two; heck, add a hundred. Who survives? Who doesn't? What is your story about.

When you are done, tack on "The End" to the end of it. Get your story ready. It's time to start writing your novel.