def findZigZagSequence(a, n):
a.sort()
mid = int((n + 1)/2)-1
a[mid], a[n-1] = a[n-1], a[mid]
# mid_n = [a[int((n + 1)/2)-1]]
# f = []
# b = []
# for i in range(mid):
# f.append(a[i])
# for i in range(mid+1,n):
# b.append(a[i])
# f.sort()
# return f+mid_n+sorted(b,reverse=True)
st = mid + 1
ed = n - 1
while(st <= n - mid+1):
if a[st] < a[st+1]:
a[st], a[st+1] = a[st+1], a[st]
st = st + 1
st = 0
while(st <= mid-1):
if a[st] > a[st+1]:
a[st], a[st+1] = a[st+1], a[st]
st = st + 1
return a
test_cases = int(input())
for cs in range (test_cases):
n = int(input())
a = list(map(int, input().split()))
arr = findZigZagSequence(a, n)
print(*arr)
