Paragraph- Sent 1: Fiery Ming Ming has always been the kind to take responsibility for her actions .
Sent 2: When she meets D at a boxing ring , the two soon become lovers .
Sent 3: D tells Ming Ming he would go to Harbin if he had $ 5 million .
Sent 4: Taking him at his word , Ming Ming goes to Brother Cat and asks him for the money .
Sent 5: When he demurs , she steals it , along with a secret box ; she manages to fight off the other gang members by incredible prowess with black flying beads , which projected at enough speed , can be deadly .
Sent 6: Brother Cat is furious she has taken the box ; and send his associates to find her .
Sent 7: As she is running away , Ming Ming bumps into an acquaintance , Tu , and passes him the money and tells him to run .
Sent 8: Tu 's special skill is to run very fast .
Sent 9: She also bumps into Nana who coincidentally is also in love with D , while escaping .
Sent 10: Mistaking Nana for Ming Ming , Tu grabs her hand and the two of them escape to Shanghai in search for D. Nana knows Tu has got the wrong person , but the lure of the $ 50 million is too strong .
Sent 11: Meanwhile , Ming Ming keeps herself hidden with the box , using her superb fighting skills to protect the two from a distance .
Sent 12: Failing to find D , all Ming Ming and Nana have is a secretive voicemail message left by him .
Sent 13: Finally , they realize that the secret that D is looking for is also connected to the box they hold .
Sent 14: Just what is this secret ... 
Question: how Ming and Nana realized that the secret that D is looking for is also connected to the box? 
Incorrect Answer: D left them a voice mail message.