What started as an errand for their mom has turned nasty for Shane Jackson, 13, and his sister Portia, 11. The package they delivered to old Mr. Blair freaked him out. Then Mr. Blair mysteriously disappeared and the kids fell through the floor into the cellar. There they found Mr. Blair, Shane's name scrawled on the wall . . . and their mom!

To read the story so far go to www.washingtonpost.com/kidspost and click on Summer Book Club. More than 30 readers entered this week:

"What's mom doing here?" wondered Portia. Her eyes traveled from her mom to the box, and it was just then that she realized there was another note in the box.

"Mr. B!" Portia exclaimed. "There's a second note in the box!"

"Take apart the clock," the note read.

-- Gabriella Studt, 9, Columbia

KidsPost's mystery is drawing to a close. Only two more "chapters" will be published -- one next Wednesday and the final one the following week, when we publish the entire story along with biographies of our authors. Don't miss out on your chance to answer the questions: What's the connection among Mr. Blair and Shane and Portia's mom? What secret does the clock hold? How will everyone get out of the basement? What happens is up to you!

Here are the rules: Your submission can be no more than 50 words. (Yes, "the" counts as a word!) We can edit your entry. The deadline is 9 a.m. Monday. You can enter by e-mailing kidspost@washpost.com (put "Mystery" in the subject line) or by faxing us at

202-496-3780. To be considered, an entry must include your name, age, address and phone number. If we publish your entry, we'll send you a KidsPost T-shirt.