In a tactical operation known as movement to contact, Alpha Co. at TBS began the first day of FieldExercise III, a weeklong training evolution that will further advance the young officers’ knowledge of tactical movement in the field, Monday.

During the early morning briefing, the instructors stressed a few points to the students. The criticalaspects of the movement-to-contact drill upon which they were about to embark are unit integrity, speed and violence of motion. Unlike a normal patrol, movement-to-contact is a hastier, more deliberate drill where the location of the enemy is suspected but not known. The goal for the young lieutenants is to close in on that enemy before losing the trail.

The 3,000 meters that each platoon negotiated is thickly wooded terrain. Along the way, combatinstructors lay in wait in concealed locations, ready to mount attacks on the students.

In the case of enemy contact, the size of the enemy matters. Because of the fast-paced nature of a movement-to-contact drill, a sniper is usually bypassedaltogether, according to combat instructors at TBS. A platoon’s firepower is usually reserved for larger elements, such as fire teams. A squad in front destroys the threat, while the rest of the platoon moves forward. The squad that was in front now picks up the rear. In this leap-frog fashion, movement-to-contact is one steady, continuous motion in one direction.

During a routine security halt, one of the lieutenants called, ‘‘Contact right!” This means an enemy has opened fire and the squad must return suppressive fire. The Marines arranged themselves into a line from which to begin their assault.

They reacted well, but they experienced a problem with one of their medium machine guns. Once the crew-served M240G was operational again, it started firing at the same time as another one on the other end of the line.

‘‘Listen,” said an instructor, who walked to the lieutenants’ position. ‘‘That’s wrong. One gun fires, and then another one. If they’re firing at the same time, you’ll run out of ammo.”

This technique of alternating machine gun fire is referred to as talking guns. It’s a simple way to confuse and suppress the enemy.

This movement-to-contact exercise was full of lessons for the new platoon leaders. It’s an exercise where many elements must come together at once in a unique synthesis of swift movement and deadly fire.

‘‘Movement to contact is a complicated puzzle,” aninstructor said during the debriefing at the end of the day.

For the lieutenants, the takeaway was large and beneficial. They added another skill set to their repertoire of leadership abilities. They continued to build on this throughout the week.

‘‘Today was tricky,” said 2nd Lt. Preston Wallace, a squad leader with Company A. ‘‘We didn’t really have an exact location on the enemy. That made things harder.”

For Wallace, the challenge of leading a squad through formidable terrain against an unknown opponent was exacerbated by his position as squad leader.

‘‘TBS is one of the hardest places to lead,” said the 23-year-old Columbia, Md., native. ‘‘Out here, you’re just another lieutenant. You have to earn the respect of your peers.”

In the fast-moving environment of Monday’s exercise, the students rose to the occasion despite theunfamiliar terrain, unknown distance from the enemy and sporadic communication problems.

‘‘The hardest thing is discovering where the enemy is going to be,” said 2nd Lt. John J. Carter, a platoon commander with the company. ‘‘It’s very hard to control units you can’t see. That’s why it’s important to have explicit communication.”