Secrets resurface, of those who could destroy an alliance even before its creation... Years later, in Kingdom Come, Batman and Superman are looking for Boy Thunder, sent by the Key into the Multivers. In these parallel realities, can they rely on their alter ego? But above all, in what condition will they find the young man? Fragilized by previous traumatic events, plagued by crises of anger and violence, will he be able to follow the steps of his mentor, or will he sink into darkness?