i need to find analitical writings on how minor charcters play a major
roll in "The Door in the Wall" by Marguerite De Angeli

I wasn't able to find any analytical writing about the minor
characters in the novel, but I found three study guides that might
help you think about which minor characters were important and the
role they played.

Those study guides are located here:
http://www.nt.net/~torino/door.html
http://www.saskschools.ca/~cathcurr/la/ditw.html
http://www.fiveinarow.com/reststop/101500.html

Some of the characters these guides mention are Robin's father, who
sends him away and who Robin wants desperately to impress; Brother
Luke, who becomes a mentor to Robin; and Sir Peter, who gives Robin
advice that may affect the way he thinks about his handicaps.