Beyond the ivy-covered wall lies an impossible garden where every plant holds a human life. And not all of them have grown the way they should.

Clara is nine the first time she steps through the door of the house at number seven on Ring Street. For three years, she believes she has simply found a refuge with Aurora and Silvana, two women who welcome her with tea and biscuits every afternoon.

Until he discovers the truth.

In the garden, tending isn't all that happens: it's also decided who flourishes… and who doesn't.

When Vanessa, the most feared girl at school, begins to feel the same pull toward the garden that Clara does, the Guardians discover something unsettling: Her plant bears ancient seals. Marks that should never have existed.

Now Clara must face a question that will change the way she sees the world:

Are some people born invasive…
or does someone make them that way?