How and why does Calvin fit in with the Murry family?

Calvin is
similar to the Murrys in that he looks at life unconventionally. They meet when Meg and Charles
Wallace run into him near the "haunted" house where Mrs. Whatsit, Mrs. Which and Mrs.
Who live. Calvin explains that he felt a "compulsion" to visit the haunted house and
mentions often having such compulsions. In other words, like Charles Wallace, Calvin listens to
his intuitions. Although he is popular at school, a good student and a basketball player, he
doesn't feel anymore at home in this conventional environment than do Meg or Charles Wallace. He
explains to Meg that while he fits in superficially, the everyday high school world really isn't
for him. Until the Murrays, he hasn't met anyone who truly understands him and who he can talk
to about subjects that matter. As he puts it after meeting the Murrays, "I feel as though I
were just being born! I'm not alone anymore!"

Like Mr. Murry, Calvin is
tall, thin and blue-eyed.  Like the Murrys, he's caring, he's open to new ideas and he has had
pain in his domestic life. If the Murry father has disappeared without a trace, Calvin suffers
because his mother, with eleven children, is overwhelmed and unable to adequately care for her
family. Calvin has so much in common with the Murrys in terms of outlook, and they fill such a
gap in his home life, that he clicks almost instantly with his new
"family."