Your symbol for the week is the Mariana Trench, which is the lowest place on the earth's surface. Located underwater in the Pacific Ocean, it's almost seven miles down -- further below sea level than Mt. Everest is above sea level.
I chose this natural feature for you to play with in your imagination because I'm hoping it will inspire you to explore the extreme depths. The coming days will be an excellent time to get better acquainted with the stuff that's at the very bottom of your world.