The classic graphic novel. Tintin and Captain Haddock peek in Professor Calculus' laboratory to find a sonic device and a very mysterious-and violent!-stranger. Realizing that Calculus' life is in danger, Tintin and the Captain rush to warn him before it's too late.

 Publisher : Little, Brown Books for Young Readers; First American Edition (September 30, 1976)
Language : English
Paperback : 62 pages
ISBN-10 : 9780316358477
ISBN-13 : 978-0316358477
Reading age : 10 - 13 years
Grade level : 3 and up
Item Weight : 9.1 ounces
Dimensions : 8.6 x 0.45 x 11.55 inches