text: After seeing a vision of King Tirian of Narnia pleading for their help in England , Peter and Edmund go to the Ketterleys ' old home in London to dig up the magic rings that Professor Kirke buried in the yard as a boy in The Magician 's Nephew to be used by Eustace and Jill to reach Narnia .
simplified: After dreaming of King Tirian in Narnia begging for their help in England , Peter and Edmund go to the Ketterleys ' old home in London to dig up the magic rings that Professor Kirke buried in the yard as a boy in The Magician 's Nephew to be used by Eustace and Jill to reach Narnia .