Tommy (Planet of the Spiders)

Tommy was a simple-minded handyman working at the Buddhist meditation centre somewhere in rural England.

When the meditation centre came under investigation (on account of Lupton's unnatural practices), Tommy had become aware of strangers coming to and from the house as well as the strange goings on there. He befriended Sarah Jane Smith and Mike Yates, who were there secretly to find out what was going on. When the blue crystal came to the house with Lupton, Tommy was eager to add it to his collection of "pretties", and took the crystal when Lupton wasn't looking, hiding it in a shoebox in a cupboard under the stairs where he often sought solitude.

Later, Lupton's followers, who often treated Tommy poorly, taunted him over how he couldn't read the DO NOT DISTURB sign on their door. After hearing this, Tommy returned to his cupboard to refer to a children's book, reading the simple text aloud. He looked into the crystal, which looked into his mind, causing him to faint. Waking up, Tommy realised that something had happened to him and he could read much better. He then went to get more books from the meditation centre's library, and was changed once more by the crystal.

Later, when the Third Doctor and Sarah Jane returned, he helped them foil the plans of Lupton's spider-possessed followers, realising that he could resist their power blast attacks. It was his innocence that protected Tommy from the spiders' blasts of power, and he faithfully stood guard outside K'anpo Rimpoche's private room, keeping Lupton's henchmen from getting to the crystal until the Doctor was able to defeat the spiders. He presumably remained a changed man afterwards. (TV: Planet of the Spiders)

When Mike Yates attended Bernice Summerfield and Jason Kane's wedding, he told the Seventh Doctor that "Tom [sent] his regards". (PROSE: Happy Endings)

Personality
Before he looked into the crystal, Tommy had the mind of a child and was slow to pick up on things, but also had a kind heart and great innocence; it was this innocence that protected him from harm. He also had a fondness for beautiful things, which he called "pretties", and collected them whenever he could. After the change, he retained his kindness with a renewed nobility of spirit to help others. (TV: Planet of the Spiders)

Behind the scenes

 * According to Terrance Dicks's novelisation of the story, following the events at the meditation centre, Brigadier Lethbridge-Stewart planned to use his influence to get Tommy a place at university. This was not derived from any information given in the televised version.
 * The children's book from which Tommy reads aloud in his cupboard under the stairs in part four is Going to School, first published by Ladybird Books in 1959.
 * During the scene in part four where Tommy reads aloud from a book of poetry in the meditation centre's library, he recites the opening verse of "The Tyger" by William Blake — which he calls "pretty", before correcting himself to "beautiful".