On July 31, 1943, Patton's 7th army is advancing from the western part of Sicily with the goal of capturing the port of Messina ahead of British forces advancing from the southeast and before the Axis can evacuate it. The 1st infantry division advancing towards Messina are stopped by forces dug in around Troina in a fortification known as the Etna line. With Troina the key to one of the few good roads leading to Messina, the 1st Infantry division, led by Major General Terry Allen, is determined to get through. Allen believes the Germans will fall back out of the town rather than dig in and cause its destruction from a battle but he is wrong.
Allen sends in infantry from the 39th combat team to assault Troina but the troops come under fire from German guns such as the PAK 40 75 mm gun, which can fire 14 rounds a minute at a range of 1969 yards. With German 88 mm guns in use as well that could fire repeatedly, the infantry withdraws to allow the Americans to bring up their own artillery in 105 and 150 mm artillery guns.
With these guns and the 62nd field artillery guns, Troina and the hills around it are soon bombarded by heavy fire that obscures it with all the smoke.
Patton believes that taking Messina will restore the name and valor of his men. For the battle, one prong under General Trescott will go down highway 111 while the other prong led by General Omar Bradley will head through the center of the island on highway 120. Unlike Palermo, though, this battle will be much tougher with Field Marshall Albert Kesselring determined to slow the Americans down as much as possible.
The first defensive position is known as Etna line and Patton is confident his troops can get through. The attack begins with the siege of Troina on August 2, 1943 with American artillery pounding German positions. However, the Germans are so well entrenched that the American firepower doesn't dislodge them. Allen decides he has to put all the infantry in to assault the highland and take the high ground. However, the infantry is quickly pinned down and stopped and Patton and his generals realizes this battle will be a bloody slaughter to the end.
After five days of bombardment and Patton determined to push through, Troina remains in German hands and Allen comes under pressure to get the job done. By August 4, the infantry that are in the hills are low on water and ammo and coming under fire from new German machine gun positions. The American infantry launch mortar rounds into the German positions but with low ammo reserves and facing a German counter attack, the American infantry manage to hold their positions nevertheless.
After a week of bloody combat, Patton' forces get the upper hand and the Germans start to pull back. The capture of Troina comes at a price with the town virtually obliterated and many dead and wounded on both sides. In the wake of this deadly toll, Allen and his aide Teddy Roosevelt Jr. are relieved of command by Omar Bradley though Patton is blamed.
Twenty miles north, Patton's advance along highway 113 is being met by German fire from the high ground. With the Germans also slowing things by demolishing key stretches of the road, General Trescott comes up with a bold plan that might give Patton Messina before the British get there.
Trescott proposes a joint army/navy attack with his troops going around the Germans and bypassing the defensive fortifications. At 9 pm at night, Allied vessels move into position and the troops go ashore and catch the German defenders completely by surprise. However, the Germans have withdrawn most of the troops to the city of Brolo under the same cover of night but the right flank of the Etna line has collapsed.
Patton likes this amphibious assault that he orders a second one for Brolo. General Trescott argues against it but Patton is unswayed and wants the attack. The generals and men under Patton are growing weary of the seemingly constant fighting and heat and tropical diseases are taking their toll as well.
Patton visits one of the field hospitals and is moved by the injuries he sees. However, when he encounters a soldier suffering from battle fatigue as well as tropical diseases, Patton becomes enraged as what he perceives as cowardice. Patton slaps the soldier across the face and yells at the soldier that he's going back to the front. Days later, Patton slaps another soldier suffering from battle fatigue in a field hospital and he is so enraged that he reaches for his trademark pistols to shoot him before he is restrained.
At 1 am on August 11, 1943, infantry under the command of General Bernard hit the shore near Bolo escorted by five destroyers and are supported by naval gunfire. However, things go wrong as tanks start to bog down and the element of surprise starts to dissipate. By sunrise, it is apparent the sneak attack has failed and naval gunfire tries to help before withdrawing for fear of an air attack. In searing heat, the American infantry use what they have to hold off the Germans until supporting naval bombardment returns at 5:45 pm. However, Italian bombers threaten to sink the firing ships and after fighting off the bombers, the navy withdraws once again.
As the day dawns on August 12, the Americans see that the Germans have completely pulled out of Brolo. Despite the cost, Patton's plan has worked as Kesselring calls for a withdrawal of all German troops in a fighting retreat.
On August 14, 1943, Patton's army moves within sight of Messina and the troops see that the Germans still have firepower to make them pay. An American tank column comes under fire from artillery protecting the German withdrawal. The tanks are ordered to withdraw until Patton himself shows up and orders them forward guns blazing. With the road cleared, the path is cleared to go to Messina.
At midnight on August 17, 1943, enemy ships are busy pulling troops out of Messina at Kesselring's orders. Hours later, American troops enter Messina unopposed and with orders to keep British troops out until Patton arrives. Despite a high fever, Patton proclaims victory at 10 am but it is a tarnished victory. When news of Patton slapping troops breaks, the furor of the American public is intense and Patton is ordered to apologize to the two soldiers he slapped. Patton goes a step further and apologizes to every division under his command.
The Allies have secured Sicily at a price to Patton's 7th army of 2,237 soldiers killed and 6,500 wounded with 24,000 overall casualties for the Allies. The battle of Sicily is seen as a pyrrhic victory with Patton going into exile as a result of his slapping the soldiers and his troops going under the command of other generals and face new battles. Patton privately worries that unless he gets his command back soon, he will never return to the war again.