diff --git a/string_algorithms.cc b/string_algorithms.cc
index cc06728..094fd93 100644
--- a/string_algorithms.cc
+++ b/string_algorithms.cc
@@ -6,6 +6,8 @@ static_assert( __cplusplus > 2020'99 );
 #include <algorithm>
 #include <exception>
 
+#include <Alepha/IOStreams/EnableExceptions.h>
+
 #include "error.h"
 #include "AutoRAII.h"
 
@@ -39,22 +41,31 @@ namespace Alepha::Hydrogen  ::detail::  string_algorithms_m
 				void
 				writeChar( const char ch ) override
 				{
+					if( C::debugExpansion ) error() << "Entry to write and got `" << ch << '`' << std::endl;
 					std::ostream current{ underlying };
 
 					if( mode == Normal and ch == sigil )
 					{
+						if( C::debugExpansion ) error() << "Normal and got `" << ch << '`' << std::endl;
 						mode= Symbol;
 						varName.str( "" );
 						return;
 					}
 					if( mode == Symbol and ch == sigil )
 					{
+						if( C::debugExpansion ) error() << "Closed symbol and got `" << ch << '`' << std::endl;
 						mode= Normal;
 						const std::string name( varName.view() );
+						if( C::debugExpansion )
+						{
+							error() << "Asked to expand `" << name << '`' << std::endl;
+						}
 						if( not name.empty() )
 						{
+							if( C::debugExpansion ) error() << "Name wasn't empty" << std::endl;
 							if( not substitutions.contains( name ) )
 							{
+								if( C::debugExpansion ) error() << "Throwing" << std::endl;
 								throw std::runtime_error{ "No such variable: `" + name +"`" };
 							}
 							if( C::debugExpansion ) error() << "Expanding variable with name `" << name << "`" << std::endl;
@@ -64,6 +75,7 @@ namespace Alepha::Hydrogen  ::detail::  string_algorithms_m
 						return;
 					}
 
+					if( C::debugExpansion ) error() << "Stashing `" << ch << '`' << std::endl;
 					if( mode == Symbol ) current.rdbuf( &varName );
 					current << ch;
 				}
@@ -76,7 +88,7 @@ namespace Alepha::Hydrogen  ::detail::  string_algorithms_m
 					{
 						if( C::debugIOStreamLifecycle ) error() << "Mode not being normal, we're throwing (" << ++throws << " times now)..." << std::endl;
 						mode= Normal;
-						throw std::runtime_error{ "Unterminated variable `" + varName.str() + " in expansion." };
+						throw std::runtime_error{ "Unterminated variable `" + varName.str() + "` in expansion." };
 					}
 				}
 		};
@@ -92,6 +104,7 @@ namespace Alepha::Hydrogen  ::detail::  string_algorithms_m
 	exports::expandVariables( const std::string &text, const VarMap &vars, const char sigil )
 	{
 		std::ostringstream oss;
+		IOStreams::EnableExceptions exc{ oss };
 
 		oss << StartSubstitutions{ sigil, vars };
 		oss << text;
diff --git a/string_algorithms.test/0.cc b/string_algorithms.test/0.cc
index 3c3887e..4c908e8 100644
--- a/string_algorithms.test/0.cc
+++ b/string_algorithms.test/0.cc
@@ -38,7 +38,7 @@ static auto init= enroll <=[]
 		},
 	};
 
-	"An exception should be thrown when there is a trailing unenclosed variable."_test <=TableTest< Alepha::expandVariables >::ExceptionCases
+	"An exception should be thrown when there is a trailing unenclosed variable."_test <=TableTest< Alepha::expandVariables >::Cases
 	{
 		{ "Complete var",
 			{ "$H$ $W$", { { "H", lambaste<="Hello" }, { "W", lambaste<="World" } }, '$' },
@@ -46,11 +46,15 @@ static auto init= enroll <=[]
 		},
 		{ "Complete var",
 			{ "$H$ $W$", { { "H", lambaste<="Hello" }, { "W", lambaste<="World" } }, '$' },
-			std::type_identity< void >{}
+			"Hello World"
 		},
 		{ "Incomplete var",
 			{ "$H$ $W", { { "H", lambaste<="Hello" }, { "W", lambaste<="World" } }, '$' },
-			std::type_identity< std::exception >{} 
+			std::runtime_error{ "Unterminated variable `W` in expansion." }
+		},
+		{ "Missing var",
+			{ "$H$ $W$", { { "W", lambaste<="World" } }, '$' },
+			std::runtime_error{ "No such variable: `H`" }
 		},
 	};