Space Pen

A pen independently developed by inventor Paul Fisher, The Space Pen has many useful abilities: it can write on greasy surfaces, under water, and (because of its pressurized interior) in the zero-G or microgravity environment of space, using a special viscous ink that resists leakage. Much more information about the pen can be found at its Wikipedia entry.

Some time before the events of [SYWTBAW], Nita is given a Space Pen of the "bullet" design by her Uncle Joel: it becomes a treasured possession, the "lucky pen" that she uses to take tests. She is extremely upset when it's stolen from her by Joanne Virella and her gang of bullies after they beat her up. Her attempts to get it back become her first efforts at wizardry. These lead to her meeting Kit for the first time, and also produce some very strange results...like Fred

Fisher's own website can be found here.