Capítulo 119: Death Pit.

Shi Lang told Sharpnel to set off the charges around the holding cells for two reasons, first was to make the enemy think that they did not care about the two prisoners. The second was to give their captured teammates a heads up, that they were here. 

Given the tactic understanding they have developed over the years, it was easy for them to guess who was the person responsible for the explosions around the holding area. Sharpnel got to work as the two people hid in the corner, waiting for Hunk to arrive. 

...

Inside the Holding Cell, Lullaby and Tian sat back to back, with their limbs tied to a motion-sensing bomb. Their faces were riddled with wounds and bruises. Their mouths were stuffed with a thick cloth. They had their freedom restricted and even voices were taken away. However, they were still communicating.