 Gonch brings the "groping grab" to school, while Hollo has made up some fake dentists appointment cards. Calley turns up very confused and upset after her night at real mum, Angela s house. Mrs. McClusky isn t pleased to find Miss Washington has left her registration class unsupervised, and further displeased to see Ronnie s chalk-covered hair. In Hollo s fake dentist appointment, he and Gonch go and see Mr. Light, their Bridge Building O.A.P. They find he s in need of some building repairs, and feeling indebted to him for saving them from French, form a plan to "borrow" building materials being used to repair the toilets. Cleaver s bag is suspended from a height, courtesy of Gonch s groping grab, and once it is retrieved, its contents are produced - a bunch of videos. A new scheme evolves involving dental cards, rented videos and Hollo s house. Ronnie s coat goes missing, but it s not the only thing: Miss Washington s purse has also disappeared. As the Staff Room was locked, suspicion falls on Gonch s mechanical groping grab. Gonch and Hollo bring building materials round to Mr. Light, but unfortunately they have plaster instead of mortar!