diff --git a/cmd/testscript/testdata/work.txt b/cmd/testscript/testdata/work.txt
index 021705c..dfd19f0 100644
--- a/cmd/testscript/testdata/work.txt
+++ b/cmd/testscript/testdata/work.txt
@@ -13,7 +13,7 @@ stderr '^temporary work directory: \Q'$WORK'\E[/\\]\.tmp[/\\]'
 stderr '^temporary work directory for file.txt: \Q'$WORK'\E[/\\]\.tmp[/\\]'
 stderr '^temporary work directory for dir[/\\]file.txt: \Q'$WORK'\E[/\\]\.tmp[/\\]'
 expandone $WORK/.tmp/testscript*/file.txt/script.txtar
-expandone $WORK/.tmp/testscript*/file.txt1/script.txtar
+expandone $WORK/.tmp/testscript*/file.txt#1/script.txtar
 
 -- file.txt --
 >exec true
diff --git a/testscript/testdata/big_diff.txt b/testscript/testdata/big_diff.txt
index f3effc0..21efffb 100644
--- a/testscript/testdata/big_diff.txt
+++ b/testscript/testdata/big_diff.txt
@@ -7,6 +7,7 @@ env
 cmpenv stdout stdout.golden
 
 -- stdout.golden --
+** RUN script **
 > cmp a b
 diff a b
 --- a
diff --git a/testscript/testdata/long_diff.txt b/testscript/testdata/long_diff.txt
index ea42157..a55b86c 100644
--- a/testscript/testdata/long_diff.txt
+++ b/testscript/testdata/long_diff.txt
@@ -110,6 +110,7 @@ cmpenv stdout stdout.golden
 >a
 >a
 -- stdout.golden --
+** RUN script **
 > cmp a b
 diff a b
 --- a
diff --git a/testscript/testdata/testscript_explicit_files.txt b/testscript/testdata/testscript_explicit_files.txt
new file mode 100644
index 0000000..1de030b
--- /dev/null
+++ b/testscript/testdata/testscript_explicit_files.txt
@@ -0,0 +1,26 @@
+# Check that we can pass an explicit set of files to be tested.
+! testscript -files foo.txtar x/bar.txtar y/bar.txtar 'y/bar#1.txtar'
+cmpenv stdout expect-stdout
+-- expect-stdout --
+** RUN foo **
+PASS
+** RUN bar **
+PASS
+** RUN bar#1 **
+> echoandexit 1 '' 'bar#1 failure'
+[stderr]
+bar#1 failure
+FAIL: $$WORK${/}y${/}bar.txtar:1: told to exit with code 1
+** RUN bar#1#1 **
+> echoandexit 1 '' 'bar#1#1 failure'
+[stderr]
+bar#1#1 failure
+FAIL: $$WORK${/}y${/}bar#1.txtar:1: told to exit with code 1
+-- foo.txtar --
+echoandexit 0 '' 'foo failure'
+-- x/bar.txtar --
+echoandexit 0 '' 'bar failure'
+-- y/bar.txtar --
+echoandexit 1 '' 'bar#1 failure'
+-- y/bar#1.txtar --
+echoandexit 1 '' 'bar#1#1 failure'
diff --git a/testscript/testdata/testscript_logging.txt b/testscript/testdata/testscript_logging.txt
index 60975fe..f0c0777 100644
--- a/testscript/testdata/testscript_logging.txt
+++ b/testscript/testdata/testscript_logging.txt
@@ -33,6 +33,7 @@ printargs section5
 status 1
 
 -- expect-stdout.txt --
+** RUN testscript **
 # comment 1 (0.000s)
 # comment 2 (0.000s)
 # comment 3 (0.000s)
@@ -43,6 +44,7 @@ status 1
 [exit status 1]
 FAIL: $$WORK${/}scripts${/}testscript.txt:9: unexpected command failure
 -- expect-stdout-v.txt --
+** RUN testscript **
 # comment 1 (0.000s)
 > printargs section1
 [stdout]
@@ -59,6 +61,7 @@ FAIL: $$WORK${/}scripts${/}testscript.txt:9: unexpected command failure
 [exit status 1]
 FAIL: $$WORK${/}scripts${/}testscript.txt:9: unexpected command failure
 -- expect-stdout-c.txt --
+** RUN testscript **
 # comment 1 (0.000s)
 # comment 2 (0.000s)
 # comment 3 (0.000s)
@@ -80,6 +83,7 @@ FAIL: $$WORK${/}scripts${/}testscript.txt:9: unexpected command failure
 [exit status 1]
 FAIL: $$WORK${/}scripts${/}testscript.txt:16: unexpected command failure
 -- expect-stdout-vc.txt --
+** RUN testscript **
 # comment 1 (0.000s)
 > printargs section1
 [stdout]
diff --git a/testscript/testdata/testscript_stdout_stderr_error.txt b/testscript/testdata/testscript_stdout_stderr_error.txt
index a69c7d0..172e056 100644
--- a/testscript/testdata/testscript_stdout_stderr_error.txt
+++ b/testscript/testdata/testscript_stdout_stderr_error.txt
@@ -9,6 +9,7 @@ cmpenv stdout stdout.golden
 > printargs hello world
 > echoandexit 1 'this is stdout' 'this is stderr'
 -- stdout.golden --
+** RUN testscript **
 >  printargs hello world
 [stdout]
 ["printargs" "hello" "world"]
diff --git a/testscript/testscript.go b/testscript/testscript.go
index 45043fd..3fe5189 100644
--- a/testscript/testscript.go
+++ b/testscript/testscript.go
@@ -22,6 +22,7 @@ import (
 	"regexp"
 	"runtime"
 	"slices"
+	"strconv"
 	"strings"
 	"sync/atomic"
 	"syscall"
@@ -136,6 +137,11 @@ type Params struct {
 	// Dir is interpreted relative to the current test directory.
 	Dir string
 
+	// Files holds a set of script filenames. If Dir is empty and this
+	// is non-nil, these files will be used instead of reading
+	// a directory.
+	Files []string
+
 	// Setup is called, if not nil, to complete any setup required
 	// for a test. The WorkDir and Vars fields will have already
 	// been initialized and all the files extracted into WorkDir,
@@ -241,24 +247,29 @@ func (t tshim) Verbose() bool {
 // RunT is like Run but uses an interface type instead of the concrete *testing.T
 // type to make it possible to use testscript functionality outside of go test.
 func RunT(t T, p Params) {
-	entries, err := os.ReadDir(p.Dir)
-	if os.IsNotExist(err) {
-		// Continue so we give a helpful error on len(files)==0 below.
-	} else if err != nil {
-		t.Fatal(err)
-	}
 	var files []string
-	for _, entry := range entries {
-		name := entry.Name()
-		if strings.HasSuffix(name, ".txtar") || strings.HasSuffix(name, ".txt") {
-			files = append(files, filepath.Join(p.Dir, name))
+	if p.Dir == "" && p.Files != nil {
+		files = p.Files
+	} else {
+		entries, err := os.ReadDir(p.Dir)
+		if os.IsNotExist(err) {
+			// Continue so we give a helpful error on len(files)==0 below.
+		} else if err != nil {
+			t.Fatal(err)
+		}
+		for _, entry := range entries {
+			name := entry.Name()
+			if strings.HasSuffix(name, ".txtar") || strings.HasSuffix(name, ".txt") {
+				files = append(files, filepath.Join(p.Dir, name))
+			}
 		}
-	}
 
-	if len(files) == 0 {
-		t.Fatal(fmt.Sprintf("no txtar nor txt scripts found in dir %s", p.Dir))
+		if len(files) == 0 {
+			t.Fatal(fmt.Sprintf("no txtar nor txt scripts found in dir %s", p.Dir))
+		}
 	}
 	testTempDir := p.WorkdirRoot
+	var err error
 	if testTempDir == "" {
 		testTempDir, err = os.MkdirTemp(os.Getenv("GOTMPDIR"), "go-test-script")
 		if err != nil {
@@ -307,10 +318,27 @@ func RunT(t T, p Params) {
 	}
 
 	refCount := int32(len(files))
+	names := make(map[string]bool)
 	for _, file := range files {
 		file := file
-		name := strings.TrimSuffix(filepath.Base(file), ".txt")
-		name = strings.TrimSuffix(name, ".txtar")
+		name := filepath.Base(file)
+		if name1, ok := strings.CutSuffix(name, ".txt"); ok {
+			name = name1
+		} else if name1, ok := strings.CutSuffix(name, ".txtar"); ok {
+			name = name1
+		}
+		// We can have duplicate names when files are passed explicitly,
+		// so disambiguate by adding a counter.
+		// Take care to handle the situation where a name with a counter-like
+		// suffix already exists, for example:
+		//	a/foo.txt
+		//	b/foo.txtar
+		//	c/foo#1.txt
+		prefix := name
+		for i := 1; names[name]; i++ {
+			name = prefix + "#" + strconv.Itoa(i)
+		}
+		names[name] = true
 		t.Run(name, func(t T) {
 			t.Parallel()
 			ts := &TestScript{
diff --git a/testscript/testscript_test.go b/testscript/testscript_test.go
index fc2e912..9cbab8f 100644
--- a/testscript/testscript_test.go
+++ b/testscript/testscript_test.go
@@ -164,7 +164,7 @@ func TestSetupFailure(t *testing.T) {
 		t.Fatal("test should have failed because of setup failure")
 	}
 
-	want := regexp.MustCompile(`^FAIL: .*: some failure\n$`)
+	want := regexp.MustCompile(`\nFAIL: .*: some failure\n$`)
 	if got := ft.log.String(); !want.MatchString(got) {
 		t.Fatalf("expected msg to match `%v`; got:\n%q", want, got)
 	}
@@ -226,18 +226,28 @@ func TestScripts(t *testing.T) {
 				fUniqueNames := fset.Bool("unique-names", false, "require unique names in txtar archive")
 				fVerbose := fset.Bool("v", false, "be verbose with output")
 				fContinue := fset.Bool("continue", false, "continue on error")
+				fFiles := fset.Bool("files", false, "specify files rather than a directory")
 				if err := fset.Parse(args); err != nil {
 					ts.Fatalf("failed to parse args for testscript: %v", err)
 				}
-				if fset.NArg() != 1 {
-					ts.Fatalf("testscript [-v] [-continue] [-update] [-explicit-exec] <dir>")
+				if fset.NArg() != 1 && !*fFiles {
+					ts.Fatalf("testscript [-v] [-continue] [-update] [-explicit-exec] [-files] <dir>|<file>...")
+				}
+				var files []string
+				var dir string
+				if *fFiles {
+					for _, f := range fset.Args() {
+						files = append(files, ts.MkAbs(f))
+					}
+				} else {
+					dir = ts.MkAbs(fset.Arg(0))
 				}
-				dir := fset.Arg(0)
 				t := &fakeT{verbose: *fVerbose}
 				func() {
 					defer catchAbort()
 					RunT(t, Params{
-						Dir:                 ts.MkAbs(dir),
+						Dir:                 dir,
+						Files:               files,
 						UpdateScripts:       *fUpdate,
 						RequireExplicitExec: *fExplicitExec,
 						RequireUniqueNames:  *fUniqueNames,
@@ -502,9 +512,27 @@ func (t *fakeT) FailNow() {
 }
 
 func (t *fakeT) Run(name string, f func(T)) {
-	f(t)
+	fmt.Fprintf(&t.log, "** RUN %s **\n", name)
+	defer catchAbort()
+	f(&subT{
+		fakeT: t,
+	})
 }
 
 func (t *fakeT) Verbose() bool {
 	return t.verbose
 }
+
+type subT struct {
+	*fakeT
+	failed bool
+}
+
+func (t *subT) Run(name string, f func(T)) {
+	panic("multiple test levels not supported")
+}
+
+func (t *subT) FailNow() {
+	t.failed = true
+	t.fakeT.FailNow()
+}