(CNN) At first, the video shows a seemingly normal urban life -- men and women shopping in the streets, with steady traffic passing by them.

A closer look shows this is a city under threat -- tarpaulins along streets hide the movements of fighters from surveillance drones and sandbags outside buildings might offer some protection from a blast from the sky or the ground.

For this is not any normal city -- this is Raqqa, the heart of ISIS's attempt to build its own state or caliphate. And it is crumbling.

Just the fact that activists filmed the secret footage now obtained exclusively by CNN is perhaps the most telling sign that the self-proclaimed capital of a reign of terror is coming to an end.

For years, anyone caught with such material would have been killed by ISIS. Phones and cameras were banned and confiscated and so-called perpetrators punished in barbaric ways.

Now it seems there is less fear, and the opponents are able to do what was once unthinkable -- to show us life in Raqqa as US-backed and other Syrian forces encircle the city in the long attempt to extinguish ISIS.

And the many scenes that we see show a ruling group as they are -- often confused, sometimes vain. We also see civilians becoming more brave, even brazen as they challenge their oppressors. This is a city that can smell its liberation.

Scenes from the caliphate

Raqqa, the last bastion of ISIS within Syria, was seized in 2014. Now, it appears that ISIS is beginning to lose its grip on the city.

One video features two Russian-speaking militants. It's hard, given heavy accents and poor audio, to know exactly what they're talking about, but it seems to revolve around lost radios and airstrikes.

Abu Huriri says to his friend: "We have a problem at the moment. I forgot even the radios. I said to Khalid, do we have them? I thought he returned them to the base. I said: let's go there.. [inaudible] .

"But apparently they've already attacked and the battle's been going for a day already."

The other man, with an accent that suggests he may be from Russia's North Caucasus region, adds: "The planes have been striking the whole day, chasing [them]."

Another scene shows Belgian fighter Abu Aisha choosing between camouflage and khaki slacks.

A third features Abu Lukhman, an Egyptian, and his colleagues from the military police, looking in vain for a Tunisian, Abu Mariam.

The snapshots are mundane, but fascinating: we are used to seeing ISIS as monsters, not as boring humans.

Commerce thrives, but what's next?

The clips show markets packed with goods and streets full of people.

The bright colors of fruits and vegetables stand out in the grainy video. For now, it seems families have been spared some of the horrors seen in other besieged ISIS-controlled cities like Mosul. One shop even seems to offer an exchange for US dollars.

Everywhere are piles of sandbags that can offer protection from airstrikes as well as restricting movements.

The civilians we see are sure to be trapped here, behind these enemy lines, perhaps held as human shields if street battles become part of the fight as they have in Mosul.

The signs of the approaching fight are clear.

The red and yellow tarps above the once open market hide what's going on from eyes in the skies.

Cement columns are packed with fuel that is then burned to create smoke screens over key positions. We see the smoke in the footage but it is unclear where it originates.

Elsewhere though, we see signs that residents are daring to dream of the end. They're spraying the word "Free" on walls and some children are adding it even on school blackboards.

Resistance takes shape

The tyrannical grip of ISIS over Raqqa is slipping, observers say.

One activist, who was afraid for his safety and spoke anonymously, said ISIS opponents allied to his organization Ahrar al-Furat were now daring to threaten some of the most feared men in Raqqa.

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"The only way we can get to these guys (ISIS informants) is by sending threats to them on their door for example. We would write a threatening message that would say something like "we know who you are. The hour of judgment is near," he said from Istanbul.

Raqqa's ISIS leadership has fled, according to activists, leaving behind a low-level command structure. These armed militiamen can be seen everywhere in the video, wandering the streets, chatting on street corners -- never far from the civilian population.

Cars filled with explosives are said to be parked on Raqqa's main streets, ready to be detonated when the battle comes.

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It's another threat to the innocents. Still these seemingly subservient residents are quietly defiant.

"The civilians began resisting ISIS in other ways like, for example, not paying their taxes, not using the currency of ISIS," the activist said. "Before residents were very scared when they interacted [with fighters.] But now they realize we have to be part of the effort to make them fail."