Spiderama. Magnus and Molly and the Floating Chairs.

A friendship fantasy story about two lovable spiders.
Worried Molly goes in search of mysterious Magnus to ask for his help to solve her small misdemeanor.
After Magnus agrees to help, they go on a fun but scary journey through the Wizards house and it's plumbing pipes to sort out the problem that they are in a serious rush to fix before the Wizard gets back home.