A Mason City woman is under arrest after allegedly assaulting the guardian of her four-year-old son, then fleeing to South Dakota with the child. Police were called to the Brick & Tile Building shortly after 10 o’clock yesterday morning after 37-year-old Joy Hendershot allegedly took the child, violating a custodial order. 35-year-old Joshua Masters of Mason City owned the get-away vehicle and was with Hendershot at the time when they were arrested by the South Dakota State Patrol late Wednesday afternoon. Masters has been charged with aiding and abetting in the violation of a custodial order. The boy was not harmed and taken into protective custody.