We had been vacationing in Big Sky, MT starting Saturday July 30th with Hotel stay in Billings, MT. Lucas woke up Tuesday complaining of a stomach ache and headache and ended up sleeping off and on in our bed the rest of the day. He also started vomiting that day and felt kind of feverish but we didn't have a thermometer to check. On Wednesday we drove to Yellowstone with him resting in the backseat, hoping we would see an improvement but didn't so Matt and I drove back to our rental after lunch and he basically slept the whole way. I gave Lucas a bath Wed night and we already started to notice weakness. He needed help getting in and out of tub and going to the bathroom. He was only taking small sips of water and he was still vomiting whatever he drank. Lucas was moaning and groaning throughout a lot of the night and we really couldn't get him to tell us what was wrong and bothering him. We decided early Thursday morning that we needed to take him into urgent care in Big Sky. We were also wondering if the high altitude was playing a role as the place we were staying at was around 7500 ft. Matt took him to urgent care/ER and I with the help of my family started packing up getting ready to leave. They gave him a bag of IV fluids with an anti-nausea as he was really dehydrated at that point. They thought some form of gastroenteritis and the doctor seemed okay with our plan to head home. We started off for home early afternoon and pulled into Mandan around 10:30. We were concerned with his unresponsiveness and weakness in his left side. Matt had to basically carry him out of our van. We called early Friday to get in to see our regular doctor and after our visit she told us we needed to go to the ER in Bismarck, so we drove to Sanford. They did a brain CT and it showed what they thought was a brain abscess in his right side which explained his left-sided weakness. They told us we needed to go to a different hospital where there was a pediatric neurologist so they prepared us that he needed surgery that night. We decided Matt would fly with Lucas and I would stay with Josie. They left the hospital around 6 pm and landed in Mpls around 7:45 pm Friday night. They took him straight to Children's Hospital in Mpls and prepped him for surgery. The surgery went fairly quick and they put in a catheter in his 3rd ventricle to drain and relieve pressure on the brain and did a ultrasound guided biopsy/aspiration of thalamus tissue to try and culture.