The Inadequate Heir (the Bridge Kingdom, #3)

The novel alternates between two perspectives: Keris Veliant, the reluctant Crown Prince of Maridrina, and Zarrah Anaphora, a lieutenant and chosen heir to the Valcottan Empire. Their nations have fought the Endless War for generations over the contested border city of Nerastis, divided by the River Anriot. A separate conflict shapes the larger political landscape: Keris's father, King Silas Veliant, has long schemed to seize Ithicana's bridge, a massive stone structure spanning the island nation's archipelago and serving as the continent's most valuable trade route.

The story opens as Keris accompanies Silas to Southwatch Island, intending to travel through Ithicana to university. Keris despises his father's warmongering, while Silas, who murdered Keris's mother, considers his bookish son a disgrace compared to the deceased elder heir, Rask. During the journey, Keris befriends an Ithicanian soldier named Raina, and the two develop a mutual attraction. The connection shatters when Keris's entourage, revealed to be elite soldiers planted by Silas, ambushes the Ithicanian escorts using intelligence from Keris's sister Lara, now married to Ithicana's King Aren Kertell. The attack launches the invasion of Ithicana from within the bridge. Raina is killed, and Keris, bound and helpless, watches her die.

In a parallel storyline, Zarrah watches from a Valcottan ship as Silas's fleet sails toward Ithicana. She urges her cousin, General Bermin, to intercept, but he follows Empress Petra's orders not to interfere. Zarrah's hatred for Maridrina is deeply personal: Silas murdered her mother during a raid when Zarrah was fourteen. Petra raised Zarrah as both a weapon of vengeance and her chosen heir.

Months later, Zarrah takes command of the Valcottan garrison in Nerastis while Keris arrives as the Maridrinian commander opposite her. The empress orders Zarrah to avoid provocative raids, hoping Silas will deplete his garrison to reinforce Ithicana. Keris, consumed by guilt over Raina's death, refuses to engage in military strategy.

One night, Zarrah crosses the Anriot to assassinate the crown prince. Her plan fails, but she steals a packet of sealed letters. An anonymous Maridrinian man pursues her across the rooftops, catches her at a dam east of the city, and saves her life when she nearly falls. He demands the letters back, and she surrenders them, but later discovers she accidentally retained one: a love letter from a woman named Tasha addressed to "O." She returns it the following night, and they debate the Endless War. He argues that both sides perpetuate violence serving only rulers' pride; she calls him a coward for refusing to act on his ideals.

Their meetings become regular. Neither reveals their identity. Keris begins sharing Maridrinian military plans so Zarrah can ambush raids before they reach civilians, and she reciprocates. The cycle of retaliatory violence begins to break. Their conversations deepen into intimacy: Keris reads to her from a book of star constellations, and she falls asleep in his arms on a rooftop.

When the empress visits and pressures Zarrah to recommit to vengeance, Zarrah tries to end the relationship. Instead, she leaps the widened spillway gap to reach the Maridrinian, and they spend the night together. At dawn, sunlight reveals his distinctive Veliant-blue eyes, and Zarrah recognizes him as Keris. She recoils in horror and flees. While crossing back in daylight, she is captured by Keris's half brother Otis.

Keris claims Zarrah as a political prisoner and transports her toward Vencia, the Maridrinian capital, hoping Valcottan forces will rescue her en route. No rescue comes. During the journey, Zarrah grows deathly ill from poison on Otis's blade, which wounded her during a beach battle. Keris forces a healer to treat her.

In Vencia, Keris presents Zarrah to Silas as a bargaining chip and places her in the royal harem under Coralyn, Silas's eldest wife, who raised Keris after his mother's death. Zarrah secretly resolves to assassinate Silas. Keris works to free both Zarrah and Aren, whom Silas holds prisoner, cultivating a relationship with the Ithicanian king. Silas forces Keris to execute Zarrah's friend and bodyguard Yrina, who was captured infiltrating the palace. Yrina, broken by the spymaster Serin's torture, forces Keris's knife into her own throat to protect their secrets.

Serin manipulates Otis into attacking Keris by revealing that Zarrah likely ordered the sinking of a ship carrying Otis's wife. Zarrah, who has climbed the palace tower to assassinate Silas, overhears the scheme and rushes to warn Keris. During the struggle, Keris shoves Otis to protect Zarrah, and Otis falls through a window to his death.

The empress refuses to negotiate for Zarrah's release, declaring she will allow Zarrah to die rather than deal with a Veliant. Devastated, Zarrah recognizes that her aunt values her more as a martyr than alive. Keris asks Aren to help coordinate an escape, offering Zarrah's promise to supply Eranahl, Ithicana's besieged capital, as incentive. Coralyn contacts Lara and Keris's warrior half sisters, who have arrived in Vencia. At a dinner for foreign ambassadors, the sisters infiltrate the palace disguised as harem dancers, then reveal themselves and attack. Coralyn unchains Aren, and battle erupts. Zarrah prepares to kill Silas but realizes his murder before witnesses would make him a martyr and condemn Keris to unending war. She refuses to strike. Coralyn detonates an explosive, takes credit for the plot, and stays behind.

Keris hides Zarrah in a false-bottomed book chest while Aren and Lara escape. Coralyn, imprisoned underground, confesses she orchestrated events to prevent peace between the nations, then slits her own wrists to keep Serin from extracting her secrets. She dies in Keris's arms. Keris smuggles Zarrah out of Vencia aboard a ship.

During the voyage to Nerastis, Keris asks Zarrah to abandon everything and disappear with him. She decides she must return to Valcotta to honor her promise to Eranahl, temper the empress's aggression, and position herself to pursue peace as future empress. On their final night, she tells him she loves him. He lowers her from the ship into the water, and she swims to shore.

In Nerastis, Keris transforms himself into a military leader. Zarrah arranges grain shipments to Eranahl, then races to Pyrinat, the Valcottan capital, when she learns Aren and Lara are heading there. The empress reveals her plan: Once Silas commits forces against Ithicana, Zarrah is to sail into Vencia's harbor, sack the city, and kill every Veliant. Zarrah accepts outwardly but resolves to commit treason, diverting her ships to help Ithicana.

At a final meeting at the dam, Zarrah tells Keris of her plans. Unable to reach her across the widened gap, he pleads with her not to go. She walks away. Keris rides to Vencia and presents Silas with a military strategy secretly designed to fail, betting that Lara's forces and an approaching typhoon will destroy his father's fleet. He also warns Silas about the empress's naval plans, ensuring Vencia's defenses are too strong for Zarrah's ships to assault.

At Southwatch, Zarrah finds the island nearly abandoned and takes it easily. Keris confronts her, revealing the attack on Eranahl is already under way. Furious at his manipulation, she strikes him unconscious and departs, ordering her fleet south as the typhoon closes in.

The typhoon destroys Silas's fleet, and Lara kills Silas. Keris inherits the throne but cannot prevent Serin from sending proof of his relationship with Zarrah to the empress before Serin throws himself from a tower. In Pyrinat, the empress confronts Zarrah with the evidence. Zarrah defends her choices and attacks her aunt, but the empress survives and sentences Zarrah to Devil's Island, Valcotta's most brutal prison, from which no one has ever escaped. Keris, upon learning of Zarrah's imprisonment, sets sail for Ithicana to seek an alliance with Aren and Lara, determined to rescue the woman he loves.