Tomorrow at Seven

A man unveils a valuable painting he bought for $50,000 and is killed. A large Black Ace card is placed on his chest, signaling a signature m.o. for the killer and setting up a chilling pattern of future victims. This marks the first Black Ace incident that authorities will try to interpret.

Thornton Drake receives a Black Ace card with the message 'At seven tomorrow night,' a taunting summons to his imminent death. The warning tightens the game and frames the killer's reach. Drake contemplates the threat while the clock ticks toward seven.

Neil Broderick, an author intent on writing about the Black Ace killer, sets out to meet Thornton Drake to gather information. He moves toward Drake's location, pursuing clues that might reveal the killer's identity. The journey marks the start of his direct involvement in the case.

During the flight to Chicago and then to the plantation, the cabin lights go out for a moment and Austin Winters is found dead with no obvious injuries. The killer's signature is already at work aboard the plane, escalating the danger around Drake and his guests. The uneasy journey continues despite the murder.

At the plantation, Clancy begins to question suspects while Neil points out that they have crossed into another state and are thus outside their jurisdiction. The dynamic among characters tightens as trust frays. Neil's presence hints at a planned strategy to uncover the killer.

Neil goes to a side room to make a phone call and signals someone outside, but the line is cut after his message. One of the pilots has departed, leaving Henderson to contend with the unfolding suspicions. The communication break isolates the investigators from outside help.

The coroner finds a letter aboard Winters intended to reveal the killer's identity if Winters dies. When the lights go out again, the letter vanishes and a sense of supernatural mischief hangs over the investigation. Tension rises as the evidence seems to slip away.

The guests are confined to their rooms after the strange happenings, and Neil uses a hidden car outside to signal someone for help. The isolation of the estate compounds the mystery as everyone becomes a suspect. The crew scrambles to keep the killer from striking again.

A real coroner shows up and Neil confronts Martha about the missing letter. In the confusion, two plain sheets and a Black Ace card replace the missing document, and Clancy and Dugan blame Neil for the disappearances. The tension peaks as trust collapses among the living.

Neil and Clancy confront Drake in his room; a groan from the next door indicates a fresh development as Henderson is found dead in a neighboring room. The investigation tightens around Neil, who possesses a skeleton key that could unlock other rooms. The plot thickens with competing theories about who is behind the killings.

Meanwhile, downstairs, Martha appears to vanish again as a mysterious hand reaches out for her. The housekeeper is seen guiding a fake coroner who is carrying Martha, signaling that the villains are closing in. The maze of misdirection grows more dangerous by the moment.

Drake leaves with Neil, and Simons disarms him, revealing Winters' confession implicating Drake. The moment reveals the true target of the murder plot and tests the will of the conspirators. The revelation raises the stakes for the remaining survivors.

The gardener Pompey enters with a gun and a hidden spike in a walking stick, leading to Drake's death. Pompey is subdued just as the danger erupts into a full confrontation. The sudden violence exposes the mastermind behind the Black Ace and shifts the power toward the police.

Two cops arrive at the scene and take credit for resolving the case, ending the immediate danger and laying claim to the investigation. The true heroes may be the outsiders who observed the scheme, but the law takes the bow. The climactic showdown is wrapped up with justice in sight.