Jerry Spinelli's Milkweed is set in turbulent Warsaw, Poland in the midst of the Second World War. The protagonist is a nameless orphaned boy. He steals food to get by and therefore, comes to identify himself as 'Stopthief'. Stopthief gets a proper name, Misha Pilsudski, when he meets Uri, the leader of a band of orphaned thieves much like himself. Uri gives Misha a past and an identity. Misha becomes the child of Russian gypsies, separated from his family by the war.
One day while he was out with Uri, Misha witnesses the 'Jackboots' in action. The Jackboots are Nazi soldiers in Poland. Misha is enamoured by their uniforms and discipline and decides that he would one day become a Jackboot himself. During one of his escapades Misha stumbles into a garden where he meets a young Jewish girl names Janina. The two talk and soon develop a friendship. Janina invites Misha to her birthday party. Misha, however, had no understanding of what birthday parties entailed. At Janina's party he panics and steals her cake. Later when Uri explains to him the concept of a birthday cake he steals a cake from one of the best bakeries in Warsaw and leaves it at her doorstep.
Nazi control over Warsaw tightens and a curfew is imposed in the city. Misha gets a bit of his earlobe shot off when he is out past curfew one evening. Misha, Janina's family and Uri and the band of theives are all forced to move into the ghettos. The Jackboots build a wall around the ghettos in an attempt to starve out the people inside. Misha becomes the only means to obtain food for Janina's family, the Milgroms. Soon even Janina joins Misha in smuggling food into the ghetto.
Uri had disappeared for a long while and Misha finally sees him one day. Uri tells him that deportations are coming and soon everyone in the ghetto will be taken to camps or chased out. Soon after it becomes clear that all the Jews hiding in the ghettos will be taken away to be killed. When Mr Milgrom hears this he begs Janina and Uri to run away when they sneak out to steal food. Janina is against this idea and refuses to leave her family, so much so that she kicks Misha when he tries to take her with him. Janina and Misha go back to the ghetto to be met by an empty room. The two run out and they see scores of Jews being herded into trucks and boxcars by the Jackboots. In the midst of the commotion Misha loses Janina in the crowd. He goes looking for her but encounters Uri who is now a Jackboot, he hits him with a club and shoots the rest of his ear off. He sees Janina herded into a boxcar by a Jackboot.
Misha is found a few days later by a farmer who takes him in. For three years Misha works for the farmer and eventually leaves. He decides to immigrate to America. In America, he tries to assimilate, changing his name to Jack and working as a salesman. However, he is quite unsuccessful, his thick accent, small build and misshapen ear not quite letting him blend in. He meets a woman named Vivian, the only person in America who ever stopped to listen to him and the two get married. Soon Vivian too grows tired of Jack's strange and inexplicable habits and leaves him whilst still pregnant.
Years later Jack meets his daughter and granddaughter when they walked into a Bag 'n Go where he worked. The two introduce themselves and talk to Jack. Katherine, Jack's daughter, asks him to give Wendy, her daughter, a middle name which she had waited for him to give. Jack names her Janina. Katherine invites Jack to come live with her and Jack agrees.
At Katherine's house, Jack spends his time gardening. He especially loves the Milkweed which he says are a symbol of endurance and survival. Katherine asks him if he would ever tell Wendy the story behind her middle name and he answers- 'someday'.
