- Captain Fred Thomas: This is Captain Fred Thomas, commanding interplanetary vehicle M1 colonization probe. To Colonel Hal Danvers, headquarters communication, planet Earth. Subject of report - arrival on the planet Mars. Landing is completely successful.
- General Winston: [reading Tillie the computer's a report] "All enemy possibilities still in effect. Disappearance: unobserved. Safety factor ignored." Just as I thought. In spite of my orders, Capt. Lazzari was unobserved. "Note: Increased possibilities that enemy is aware of human presence. Note: Increased possibilities that enemy is not visible to human sight." What's it mean by that?
- Colonel Hal Danvers: A computer always reveals the obvious with the felicity of an elephant. No one saw the enemy, i.e., invisible.
- Captain Jack Buckley: [coming upon the location of a vanished crewman] Lazzari was right here, wasn't he?
- Major Charles 'Chuck' Merritt: [over the radio] Yes.
- Captain Jack Buckley: I hate to say it - it sounds crazy - but... there's no sign that Lazzari was ever even here. No struggle. Nothing. The enemy must really be invisible, like Tillie says.
- Major Charles 'Chuck' Merritt: Can you get that metal loose?
- [Buckley easily lifts the twisted metal that Lazzari found difficult to raise]
- Captain Jack Buckley: I take it all back, skipper. There's blood on this thing.
- Major Charles 'Chuck' Merritt: There's been a mishap, General. Capt. Lazzari's in trouble. Request permission to leave the vehicle immediately to go to his assistance.
- General Winston: Request under... consideration, Major. First, I want the facts. Was Capt. Lazzari attacked? If affirmative, by what?
- Major Charles 'Chuck' Merritt: [holding back annoyance] I don't know, sir.
- General Winston: He was under constant surveillance?
- Major Charles 'Chuck' Merritt: He was temporarily blocked from view behind wreckage of the M-1.
- General Winston: Well, how do you know ANYTHING happened to him?
- Major Charles 'Chuck' Merritt: He screamed for help.
- Major Charles 'Chuck' Merritt: Okay, Lazzari, let's have it again.
- Captain Paul Lazzari: One: Descend to base of vehicle and wait for orders
- Captain Jack Buckley: [clapping] Hey, very good. You got that right that time.
- Major Charles 'Chuck' Merritt: Shut up, Buckley.
- Captain Paul Lazzari: Two: On command, proceed with caution to target, keeping always under observation from the vehicle.
- Major Charles 'Chuck' Merritt: Purpose?
- Captain Paul Lazzari: Reconnoiter target for indication of hostile action against personnel of previous probe, namely M-1, which may have lead to their demise.
- Major Charles 'Chuck' Merritt: Mission?
- Captain Paul Lazzari: Gather up all evidence of exact nature of enemy, if any, and bring it back to the vehicle.
- [Maj. Merrit gives him a look]
- Captain Paul Lazzari: Uh, safely.
- [Lazzarri has stepped out of view, a procedural no-no]
- Captain Paul Lazzari: I'm sorry, but there's an odd-looking piece of metal buried back there. No elements can damage it the way it shows. Strange marks on it like scratches.
- [epilogue]
- Control Voice: Battle: joined. Casualties? Yes. Resolution: victory... of a sort, a painful step from the crib of destiny. On another day, a friend, perhaps, instead of a deadly peril, part of the saga of the space pioneers.
- Lieutenant Jim Bowman: Hello, Fred? Hello? You read me?
- Captain Fred Thomas: Loud and clear.
- Lieutenant Jim Bowman: [relieved] Just checking. See anything out there?
- Captain Fred Thomas: Mars. That's all. Not a sign of a single living thing.
- General Winston: [sternly] Mr. Jerome, we are going to continue this mission as planned until it can be marked "accomplished."
- [prologue]
- Control Voice: In the vast immensities of cosmic space, bold adventurers streak their way to join battle with strange enemies on strange worlds - the alien, the unknown, perhaps even the invisible - armed only with Man's Earthbound knowledge.