Naturally, the Hive Mind would have none of that. A small splinter of Hive Fleet Kraken was sent to retrieve the missing biological material. Meanwhile, on the nameless planet, a random band of rampaging Orks poured from underground caverns and attacked the science outpost. The guards put up a brave fight, but didn't stand much of a chance. The outpost was overrun. Some of the men tried to escape with the invaluable Tyranid samples, a couple barrels of pickeled rippers and some vials of Tyranid DNA (make of that what you will), but they didn't make it very far.
Just as the victorious band of Orks was returning to the entrace to their underground camp, several large spores crashed down on the opposite side of the river. These burst open, and out poured the small Tyranid force sent to retrieve the lost samples. The Orks, of course, had no idea what the Tyranids were after, but weren't about to let anyone make off with their hard-earned loot. And they also needed to protect the entrance to their lair, lest many Ork children be slaughtered in their beds. Or wherever it is they sleep.
Here are the initial deployments. At the far left of the first picture is one of the objectives, the entrance to the Ork's underground camp. On the right of the first pictures is another objective, the barrels of preserved ripper remains. In the middle of the second picture is the third and final objective, the vials of Tyranid DNA.
Here is the whole battlefield at the start of the battle. Before the game, on a whim I suggested that we make the river that runs across most of the table count as dangerous terrain. This would come back to haunt me later. We eventually decided that it was dangerous because the water was full of tentacle monsters that would try to drag down and eat anything that entered the water.
In the Ork's first turn, they were hesitant to attempt to cross the river full of tentacle monsters. But the unit containing the Weirdboy moved near the edge of the river, and the Weirdboy teleported them all across the river toward the Tyranid horde. The rest of the Ork army didn't do much, except take a few long ranged pot shots.
On the Tyranid turn, the Carnifex fired his barbed strangler at the Orks on the other side of the river, killing several. The two Zoanthropes fired at the Mega Armored Orks with the warboss, and killed one.
It might seem like the Weirdboy teleporting his unit to within range of the Tyranid hormagaunts was rather suicided... and, as it turns out, it was. The hormagaunts charged the unit, killing all but the weirdboy in combat, and running him down and devouring him in the sweeping advance.
On the second Ork turn, their looted Basilisk came on in reserve. It fired on the massed hormagaunts, was on target, and killed several. The rest of the Ork army mostly stayed still and took more inneffective pot shots at the Tyranids. They did, after all, already control two of the three objectives. And they weren't about to risk the tentacle monsters in the river.
On the Tyranid turn, their unit of gargoyles dropped down from the sky on the other side of the river. They fired at the unit of Orks, and then assaulted. They killed many, but the Ork unit held. The Hive Tyrant fired at the looted vehicle and immobilized it.
Meanwhile, the hormagaunts charged toward the Ork unit across the river from them. Not having experienced the river tentacle monsters before, they didn't realize the danger. A few of them were dragged to their deaths in the river, and the Orks made short work of the rest of them as they tried to claw their way up the opposite bank.
On the next Ork turn, they reserve unit of stormboys, and another unit of Orks showed up. The Warboss and his retinue charged in to help finish off the gargoyles.
Several of the mega-armored Orks had been killed by the Zoanthropes, leaving only three of them with the Warboss. The flying hive tyrant flew over the river and charged into the Warboss's retinue. He managed to kill two of the nobz. The remaining nob and the Warboss did two wounds to the Hive Tyrant, but the Tyrant had won the combat. The nob turned to flee, but the Warboss killed him for his cowardice.
On the same turn, the other Hive Tyrant fired on the looted vehicle again, destroying its only weapon. The carnifex with the barbed strangler continued firing at the unit of Orks near the entrance to the Ork camp. A unit of Gaunts stayed in control of the Tyranid DNA vials.
On the next turn, the Ork reserves advanced, and another unit of Ork boys showed up, this time on the Tyranid side of the river. The unit of Orks near the Warboss charged in to help their leader fight the flying Hive Tyrant, but didn't do much good. The Tyrant finished off the Warboss. The newly arrived Ork unit fired on the other Hive Tyrant, killing one of his tyrant guards.
There wasn't much action on the tyranid turn, but the genestealers were still being kept in reserve, ready to go towards either of the two other objectives, wherever they were needed.
The huge unit of stormboyz finally reached the combat with the flying Hive Tyrant. They charged in, having over fifty attacks. They managed to to a single wound. The Hive Tyrant killed several of them, but the combat would continue.
On the Tyranid turn, the genestealers were finally comitted to action. They were sent across the river to help out the surrounded flying Hive Tyrant. Of the 12 genestealers, 4 of them were killed by the tentacle monsters. Those tentacle monsters were pretty deadly. What was left of them charged in. The Orks did managed to drag down the Hive Tyrant, but the genestealers slaughtered many, and chased down those who fled. They then consolodated around the barrels of rippers. The Carnifex and Zoanthropes finally finished off the Ork unit that was guarding the entrance to the Ork camp.
After that, the game came to an end. The Tyranids controlled two objectives, both of the Tyranid organic samples. The Orks still controlled the entrance to their camp, which allowed them to quickly escape the Tyranids and live to fight another day.