A Promise (An Attack on Titan Fanfic: Erwin Smith)

Underground Chase

The humid air slapped her cheeks as Isanna soared above the cracked streets that snaked through the Underground City, whizzing past cracked buildings as the swishing of her 3DM gear lines sliced the air and guided her zipping figure. 

They were just behind the Military Police that covered the vanguard of their impromptu formation, and just ahead of them were the three flying thugs.

One look and Isanna could tell their proficiency with the vertical maneuvering gear; she was definitely impressed. 

Her eyes caught a distant bridge overlooking the street, forming a particularly low arch. Isanna watched with mild amusement how the thugs dived downwards, one of them boldly pushing through a man that was innocently pulling a wheelbarrow holding a few sacks. They merged in the shadows below the bridge and disappeared from her sight.  

The Military Police was caught in a surprise and abruptly came to a halt just a few meters from the arch, their figures hanging beside the buildings as hooks suspended them; not daring to dive that low enough. 

The Survey Corps soldiers were a different breed, however. A smug smirk formed on Isanna's lips as she shot a hook line on the side of the bridge and dived down, her body declining and using the momentum to swing through the extremely low arch while her comrades did the same. Because they were just built differently like that. 

Once Isanna reached the other side, she shot two hooks to the buildings on each side of the street and propelled her body upwards, flipping her body in midair before she continued her pursuit of the thugs. 

"They're quick." The raven turned to her left to see Mike gliding through the air just like her, his fixed eyes on the trio. 

Not long, the criminals picked up their pace and made a sudden sharp turn on a pillar of thick rocky earth that was rooted deep on the ground and stretched high up to the grounded ceiling of the Underground. 

They're testing us, Isanna thought with a smirk as she and her comrades hooked a line on the pillar and whirled around the structure, her eyes catching the way one of the trio shot back a look at them. 

The undercut guy. 

As the chase led back to the city, the group of three then decided to part ways. Two of their soldiers made a turn to each side to follow the ones who had changed courses, while Erwin, Mike and Isanna remained in their route; three pairs of eyes fixed on the figure who seemed to be their leader.  

Isanna watched with slightly widened eyes how the undercut guy suddenly picked up his pace, shooting his figure in a blurry line through the narrow streets and disappeared into one of the windows of the aged buildings, leaving a trail of gas behind. 

"He's not planning on making this easy for us, huh?" The raven chuckled as Erwin ordered Mike to go ahead and intercept him from the front, who promptly obeyed and zoomed past their line of three, forwards. 

Erwin and Isanna flew past the building where the thug had disappeared into, before the former made a quick U-turn and snapped forward, blades already brandished just as the figure of the undercut guy jumped out of a window. However, he hooked a line to the next building and zipped away just a few inches before Erwin's blade could reach him. The thug flew away and disappeared into a short tunnel of fragile bricks that was already close to toppling down.  

Isanna had stopped atop a small building, watching with interest as Mike leaped down and crashed through the tumbling bricks of the tunnel, shoving the undercut thug beneath the rubble. As the two figures rammed through a tower of crates and landed on the ground, both men wasted no time and engaged into a battle; Mike wielding two of his blades while the other raised a sharp dagger.