carried her back to base.

It wasn't until the next morning that he discovered that it was the body of his sister.

She was only 20 years old.

There was no time for him to pause, to mourn. This relentless war is not over.

Into Raqqa

Yet along with the grief, there is excitement.

Driving to the front lines in one of the few armored vehicles available to the Kurdish YPG militia that forms part of the SDF, soldiers play a popular tune aimed against ISIS and its leader, Abu Bakr al-Baghdadi.

"We will put Baghdadi's head under our feet and we will be victorious," the tune goes.

Artillery whizzes overhead, aimed at ISIS positions deep inside Raqqa. Holes have been punched in the 1,300-year-old wall encircling the old city to open it up to advancingSDF's closest allies is clear -- from the artillery that pounds throughout the night to newly asphalted roads that speed Kurdish and Syrian Arab forces toward their goal.

And the involvement is welcomed as we became the first journalists inside the walls of the old city since ISIS took it over.

"You are Americans?" a smiling soldier asks in broken English. "I love the Trump!"

On the campaign trail last year, Donald Trump promised to wipe out the terror group.

That day may be getting closer, but the fighting is still intense. Families and neighborhoods are riven, and Syria's multi-ethnic society has been torn at the seams.