Bogdan Galayda is just 22 – he is a history student making history himself.
For the past week he has been making Molotov cocktails – bottles full of fuel that he intends to throw at the Russian army if they invade his beloved city.
“Everyday we make more than a thousand bottles and if the enemy comes to my city we will make many more than that,” he told me, showing me around his secret armoury in central Odesa.
Bogdan is part of this city’s growing resistance defence force – ordinary men and women determined to defend their city.
Just a few miles away at a community centre, women are cutting up pieces of fabric and hand-tying them to netting.
They are making camouflage so that Odesa’s defences can be hidden.
Olha Poliuha, a 22-year-old English teacher, has volunteered with her mother.
She said: “This is really important and we are working around the clock to make more. We will not stop and we will not give in.
“I almost think that we have been preparing for this for many years. Russia has been threatening us for so long.
“They have been threatening our way of life, our language, our culture. It’s like everything has come down to this point in time. Ukraine will not give up. Russia will not win.”
Odesa is Ukraine’s third largest city and is strategically important to Vladimir Putin. If he can take Odesa then he could cut off Ukraine from the sea. Which is why it is one of the main targets for the Russian offensive.
Russian forces are believed to be close by and advancing from the south. There have been reports that Russian warships are along the coast, but not confirmed.
Thousands of men have joined the army in the past week in Odesa.
We were taken to a military base in the centre of the city. It will be turned into a field hospital should soldiers get injured in fighting, we are told. Blood has been donated and nurses are on hand.
Vladimir Nagorny was a film producer before the war, now he’s second in command of this army unit.
“We are not frightened to die, we are ready to die. We will not allow Russia to dictate what happens in this country. We will not allowed them to turn us into a Russian state. Never.”
Inside the base we meet soldiers having lunch in the mess. It is dark and cramped.
The men eat while they can. They sleep where they can.
Odesa is bracing itself for war now, and dark days could lie ahead.