diff --git a/ArcFormats/ArcFormats.csproj b/ArcFormats/ArcFormats.csproj
index 6ba86b06..965b6bcf 100644
--- a/ArcFormats/ArcFormats.csproj
+++ b/ArcFormats/ArcFormats.csproj
@@ -133,6 +133,9 @@
     <Compile Include="MnoViolet\ImageDIF.cs" />
     <Compile Include="Nexas\ImageGRP.cs" />
     <Compile Include="NitroPlus\ArcNPK.cs" />
+    <Compile Include="NitroPlus\WidgetNPK.xaml.cs">
+      <DependentUpon>WidgetNPK.xaml</DependentUpon>
+    </Compile>
     <Compile Include="NonColor\ArcDAT.cs" />
     <Compile Include="Crc64.cs" />
     <Compile Include="NonColor\WidgetNCARC.xaml.cs">
@@ -593,6 +596,10 @@
       <SubType>Designer</SubType>
       <Generator>MSBuild:Compile</Generator>
     </Page>
+    <Page Include="NitroPlus\WidgetNPK.xaml">
+      <SubType>Designer</SubType>
+      <Generator>MSBuild:Compile</Generator>
+    </Page>
     <Page Include="NonColor\WidgetNCARC.xaml">
       <SubType>Designer</SubType>
       <Generator>MSBuild:Compile</Generator>
diff --git a/ArcFormats/NitroPlus/ArcNPK.cs b/ArcFormats/NitroPlus/ArcNPK.cs
index e3a06f82..4b035826 100644
--- a/ArcFormats/NitroPlus/ArcNPK.cs
+++ b/ArcFormats/NitroPlus/ArcNPK.cs
@@ -28,8 +28,9 @@ using System.Collections.Generic;
 using System.ComponentModel.Composition;
 using System.IO;
 using System.IO.Compression;
-using System.Linq;
 using System.Security.Cryptography;
+using GameRes.Formats.Properties;
+using GameRes.Formats.Strings;
 
 namespace GameRes.Formats.NitroPlus
 {
@@ -47,6 +48,11 @@ namespace GameRes.Formats.NitroPlus
         public bool IsCompressed { get { return Size < UnpackedSize; } }
     }
 
+    public class Npk2Options : ResourceOptions
+    {
+        public byte[] Key;
+    }
+
     internal class NpkArchive : ArcFile
     {
         public readonly Aes Encryption;
@@ -141,8 +147,14 @@ namespace GameRes.Formats.NitroPlus
                 entry.UnpackedSize = index.ReadUInt32();
                 index.Read (name_buffer, 0, 0x20); // skip
                 int segment_count = index.ReadInt32();
-                if (segment_count <= 0)
+                if (segment_count < 0)
                     return null;
+                if (0 == segment_count)
+                {
+                    entry.Offset = 0;
+                    dir.Add (entry);
+                    continue;
+                }
                 entry.Segments.Capacity = segment_count;
                 uint packed_size = 0;
                 bool is_packed = false;
@@ -169,6 +181,8 @@ namespace GameRes.Formats.NitroPlus
 
         public override Stream OpenEntry (ArcFile arc, Entry entry)
         {
+            if (0 == entry.Size)
+                return Stream.Null;
             var narc = arc as NpkArchive;
             var nent = entry as NpkEntry;
             if (null == narc || null == nent)
@@ -183,11 +197,28 @@ namespace GameRes.Formats.NitroPlus
             return new NpkStream (narc, nent);
         }
 
+        public override ResourceOptions GetDefaultOptions ()
+        {
+            return new Npk2Options { Key = GetKey (Settings.Default.NPKScheme) };
+        }
+
+        public override object GetAccessWidget ()
+        {
+            return new GUI.WidgetNPK();
+        }
+
         byte[] QueryEncryption ()
         {
-            if (0 == KnownKeys.Count)
-                return null;
-            return KnownKeys.Values.First();
+            var options = Query<Npk2Options> (arcStrings.ArcEncryptedNotice);
+            return options.Key;
+        }
+
+        byte[] GetKey (string title)
+        {
+            byte[] key;
+            if (KnownKeys.TryGetValue (title, out key))
+                return key;
+            return key;
         }
     }
 
diff --git a/ArcFormats/NitroPlus/WidgetNPK.xaml b/ArcFormats/NitroPlus/WidgetNPK.xaml
new file mode 100644
index 00000000..a2f9554f
--- /dev/null
+++ b/ArcFormats/NitroPlus/WidgetNPK.xaml
@@ -0,0 +1,9 @@
+<Grid x:Class="GameRes.Formats.GUI.WidgetNPK"
+      xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+      xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+      xmlns:p="clr-namespace:GameRes.Formats.Properties"
+      MaxWidth="250">
+    <ComboBox Name="Scheme" Width="180"
+              ItemsSource="{Binding}"
+              SelectedValue="{Binding Source={x:Static p:Settings.Default}, Path=NPKScheme, Mode=TwoWay}"/>
+</Grid>
diff --git a/ArcFormats/NitroPlus/WidgetNPK.xaml.cs b/ArcFormats/NitroPlus/WidgetNPK.xaml.cs
new file mode 100644
index 00000000..ba9a249d
--- /dev/null
+++ b/ArcFormats/NitroPlus/WidgetNPK.xaml.cs
@@ -0,0 +1,18 @@
+using System.Windows.Controls;
+using System.Linq;
+using GameRes.Formats.NitroPlus;
+
+namespace GameRes.Formats.GUI
+{
+    /// <summary>
+    /// Interaction logic for WidgetNPK.xaml
+    /// </summary>
+    public partial class WidgetNPK : Grid
+    {
+        public WidgetNPK ()
+        {
+            InitializeComponent();
+            Scheme.ItemsSource = NpkOpener.KnownKeys.Keys.OrderBy (x => x);
+        }
+    }
+}
diff --git a/ArcFormats/Properties/Settings.Designer.cs b/ArcFormats/Properties/Settings.Designer.cs
index b820742d..5dc31d96 100644
--- a/ArcFormats/Properties/Settings.Designer.cs
+++ b/ArcFormats/Properties/Settings.Designer.cs
@@ -585,5 +585,17 @@ namespace GameRes.Formats.Properties {
                 this["BELLTitle"] = value;
             }
         }
+        
+        [global::System.Configuration.UserScopedSettingAttribute()]
+        [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
+        [global::System.Configuration.DefaultSettingValueAttribute("")]
+        public string NPKScheme {
+            get {
+                return ((string)(this["NPKScheme"]));
+            }
+            set {
+                this["NPKScheme"] = value;
+            }
+        }
     }
 }
diff --git a/ArcFormats/Properties/Settings.settings b/ArcFormats/Properties/Settings.settings
index 16dc5afc..a881c3cd 100644
--- a/ArcFormats/Properties/Settings.settings
+++ b/ArcFormats/Properties/Settings.settings
@@ -143,5 +143,8 @@
     <Setting Name="BELLTitle" Type="System.String" Scope="User">
       <Value Profile="(Default)" />
     </Setting>
+    <Setting Name="NPKScheme" Type="System.String" Scope="User">
+      <Value Profile="(Default)" />
+    </Setting>
   </Settings>
 </SettingsFile>
\ No newline at end of file
diff --git a/ArcFormats/app.config b/ArcFormats/app.config
index fe5f6783..f8cdb6fc 100644
--- a/ArcFormats/app.config
+++ b/ArcFormats/app.config
@@ -145,6 +145,9 @@
             <setting name="BELLTitle" serializeAs="String">
                 <value />
             </setting>
+            <setting name="NPKScheme" serializeAs="String">
+                <value />
+            </setting>
         </GameRes.Formats.Properties.Settings>
     </userSettings>
 <startup><supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.5"/></startup></configuration>