Nobunaga's Ninja Ban Tarozaemon gives clues to Jirobo and Sagen about the whereabouts of the Jizo Bodhisattva statue, respectively in two parts. Jirobo finds himself all alone as he takes a trip to the mountains with an entire Iga Ninja army, as he must guard Kanetsugu's secret. 
You could say it's an unexpected ambush.
Se podría decir que es 
una emboscada inesperada.
Se podría decir que es 
una emboscada inesperada.
passée inaperçue jusqu’ici.
Digamos que é uma emboscada inesperada.