diff --git a/lib/heap_sort.rb b/lib/heap_sort.rb
index 6b692e4..81316de 100644
--- a/lib/heap_sort.rb
+++ b/lib/heap_sort.rb
@@ -1,8 +1,23 @@
-
+# require_relative "min_heap"
 
 # This method uses a heap to sort an array.
-# Time Complexity:  ?
-# Space Complexity: ?
+# Time Complexity:  O(nlogn)
+# Space Complexity: O(1)
 def heapsort(list)
-  raise NotImplementedError, "Method not implemented yet..."
+
+  return list if list.length - 1 <= 1
+
+  heap = MinHeap.new
+
+  list.each do |value|
+    heap.add(value)
+  end
+
+  result = []
+  
+  list.length.times do
+    result << heap.remove
+  end
+
+  return result
 end
\ No newline at end of file
diff --git a/lib/min_heap.rb b/lib/min_heap.rb
index 6eaa630..ec0b131 100644
--- a/lib/min_heap.rb
+++ b/lib/min_heap.rb
@@ -14,10 +14,11 @@ def initialize
   end
 
   # This method adds a HeapNode instance to the heap
-  # Time Complexity: ?
-  # Space Complexity: ?
+  # Time Complexity: O(logn)
+  # Space Complexity: O(1)
   def add(key, value = key)
-    raise NotImplementedError, "Method not implemented yet..."
+    @store << HeapNode.new(key, value)
+    heap_up(@store.length - 1)
   end
 
   # This method removes and returns an element from the heap
@@ -25,7 +26,14 @@ def add(key, value = key)
   # Time Complexity: ?
   # Space Complexity: ?
   def remove()
-    raise NotImplementedError, "Method not implemented yet..."
+    return nil if @store.empty?
+
+    swap(0, @store.length - 1)
+    result = @store.pop
+    heap_down(0)
+    return result.value
+
+
   end
 
 
@@ -44,10 +52,10 @@ def to_s
   end
 
   # This method returns true if the heap is empty
-  # Time complexity: ?
-  # Space complexity: ?
+  # Time complexity: O(1)
+  # Space complexity: O(1)
   def empty?
-    raise NotImplementedError, "Method not implemented yet..."
+    return if @store.empty? 
   end
 
   private
@@ -55,17 +63,41 @@ def empty?
   # This helper method takes an index and
   #  moves it up the heap, if it is less than it's parent node.
   #  It could be **very** helpful for the add method.
-  # Time complexity: ?
-  # Space complexity: ?
+  # Time complexity: O(logn)
+  # Space complexity: O(1)
   def heap_up(index)
-    
+    return if index == 0 
+    parent_index = (index - 1) / 2
+    if @store[parent_index].key > @store[index].key
+      swap(index, parent_index)
+      heap_up(parent_index)
+    end
   end
 
   # This helper method takes an index and 
   #  moves it up the heap if it's smaller
   #  than it's parent node.
   def heap_down(index)
-    raise NotImplementedError, "Method not implemented yet..."
+    return if index >= @store.length - 1
+    
+    left_index = index * 2 + 1
+    right_index = index * 2 + 2
+
+    return if !@store[left_index] && !@store[right_index]
+
+    smallest = left_index
+
+    if left_index
+      if (right_index < @store.length) && (@store[right_index].key < @store[left_index].key)
+        smallest = right_index
+      end
+
+      if @store[smallest].key < @store[index].key
+        swap(index, smallest)
+      end
+      heap_down(smallest)
+    end
+
   end
 
   # If you want a swap method... you're welcome
diff --git a/test/heapsort_test.rb b/test/heapsort_test.rb
index 34402ac..7ce79b7 100644
--- a/test/heapsort_test.rb
+++ b/test/heapsort_test.rb
@@ -1,6 +1,6 @@
 require_relative "test_helper"
 
-xdescribe "heapsort" do
+describe "heapsort" do
   it "sorts an empty array" do
     # Arrange 
     list = []
diff --git a/test/min_heap_test.rb b/test/min_heap_test.rb
index 186d4c2..d66da01 100644
--- a/test/min_heap_test.rb
+++ b/test/min_heap_test.rb
@@ -52,25 +52,25 @@
   end
 
   it "can remove nodes in the proper order" do
-   # Arrange
-   heap.add(3, "Pasta")
-   heap.add(6, "Soup")
-   heap.add(1, "Pizza")
-   heap.add(0, "Donuts")
-   heap.add(16, "Cookies")
-   heap.add(57, "Cake")
+    # Arrange
+    heap.add(3, "Pasta")
+    heap.add(6, "Soup")
+    heap.add(1, "Pizza")
+    heap.add(0, "Donuts")
+    heap.add(16, "Cookies")
+    heap.add(57, "Cake")
 
-   # Act
-   removed = heap.remove
+    # Act
+    removed = heap.remove
 
-   # Assert
-   expect(removed).must_equal "Donuts"
+    # Assert
+    expect(removed).must_equal "Donuts"
 
-   # Another Act
-   removed = heap.remove
+    # Another Act
+    removed = heap.remove
 
-   # Another assert
-   expect(removed).must_equal "Pizza"
+    # Another assert
+    expect(removed).must_equal "Pizza"
 
   # Another Act
   removed = heap.remove