This installment was originally published in Look and Learn issue no. 406 on 25 October 1969.
The Deadly Formula (continued . . .)
This installment was originally published in Look and Learn issue no. 402 on 27 September 1969.
The Invisible Man (continued . . .)
This installment was originally published in Look and Learn issue no. 393 on 26 July 1969.
