Episode 57 of The Trigan Empire
The Lost Valley
aka The Nobes
De vergeten vallei (Dutch title)
The Forgotten Valley (Dutch title, translated)
Written by Mike Butterworth
Illustrated by Don Lawrence
The Lost Valley was originally published in 8 installments in issues 740 (20 March 1976) to 747 (8 May 1976) of Look and Learn magazine.
It is reprinted in the Don Lawrence Collection Volume 12, The Green Smog.
740 741 742 743 744 745 746 747
Plot summary (Dutch)
MediaFire via British Comics Compilations